/usr/lib/libnss3.so: version `NSS_3.19.1' not found

Hello,

I am unable to build libreoffice 5.1.2.2 on Slackware 14.1:
---
$ ./autogen.sh --prefix=/opt/libreoffice-5.1.2.2 \
 --without-doxygen \
 --without-junit \
 --with-external-tar=/tmp/build/libreoffice/libreoffice-5.1.2.2-tar \
 --disable-gtk \
 --enable-gtk3 \
 --disable-tde \
 --disable-kde4 \
 --disable-randr \
 --without-java
$ make
[...]
[build DEP] LNK:CppunitTest/libtest_writerperfect_stream.so
[build LNK] CppunitTest/libtest_writerperfect_stream.so
DynamicLibraryManagerException: "Failed to load dynamic library: 
/tmp/build/libreoffice/libreoffice-5.1.2.2/workdir/LinkTarget/CppunitTest/libtest_oox_tokenmap.so
/usr/lib/libnss3.so: version `NSS_3.19.1' not found (required by 
/tmp/build/libreoffice/libreoffice-5.1.2.2/instdir/program/libssl3.so)"
Path is 
'/bin:/sbin:/usr/bin:/usr/sbin:/usr/games:/usr/local/bin:/usr/local/sbin:/usr/local/games:/home/yugiohjcj/.cabal/bin:/home/yugiohjcj/fpc-2.4.2/bin:/home/yugiohjcj/documents/downloads/software/eclipse-standard-luna-R-linux-gtk:/home/yugiohjcj/documents/downloads/software/eclipse-modeling-luna-R-linux-gtk:/home/yugiohjcj/documents/downloads/software/eclipse-modeling-juno-SR1-linux-gtk:/home/yugiohjcj/documents/downloads/software/kermeta-1.4.1-galileo-linux_x86:/home/yugiohjcj/documents/downloads/software/apache-ant-1.9.4/bin:/home/yugiohjcj/apps/maven/apache-maven-3.0-SNAPSHOT/bin:/home/yugiohjcj/documents/downloads/software/WTK2.5.2/bin:/home/yugiohjcj/bin:/home/yugiohjcj/mvn/bin:/opt/texlive/2015/bin/i386-linux'

Error: a unit test failed, please do one of:
make CppunitTest_oox_tokenmap CPPUNITTRACE="gdb --args"
    # for interactive debugging on Linux
make CppunitTest_oox_tokenmap VALGRIND=memcheck
    # for memory checking
make CppunitTest_oox_tokenmap DEBUGCPPUNIT=TRUE
    # for exception catching

make[1]: *** [/tmp/build/libreoffice/libreoffice-5.1.2.2/workdir/CppunitTest/oox_tokenmap.test] 
Error 1
make[1]: *** Waiting for unfinished jobs....
make: *** [build] Error 2
---

It seems to be a problem with libnss3 because I can see:
/usr/lib/libnss3.so: version `NSS_3.19.1' not found (required by 
/tmp/build/libreoffice/libreoffice-5.1.2.2/instdir/program/libssl3.so)

I thought that the libnss3 version installed on my system was not the good one.
Well, I have the mozilla-nss-3.15.2 package installed on my system containing the 
/usr/lib/libnss3.so library:
$ ldd /usr/lib/libnss3.so 
        libnssutil3.so => /usr/lib/libnssutil3.so (0xb75d4000)
        libplc4.so => /usr/lib/libplc4.so (0xb75cf000)
        libplds4.so => /usr/lib/libplds4.so (0xb75cb000)
        libnspr4.so => /usr/lib/libnspr4.so (0xb758d000)
        libpthread.so.0 => /lib/libpthread.so.0 (0xb7537000)
        libdl.so.2 => /lib/libdl.so.2 (0xb7532000)
        libc.so.6 => /lib/libc.so.6 (0xb73a7000)
        libz.so.1 => /usr/lib/libz.so.1 (0xb7391000)
        librt.so.1 => /lib/librt.so.1 (0xb7388000)
        /lib/ld-linux.so.2 (0xb7745000)

On the bug tracker [1], Eike Rathke asked me to check what ldd instdir/program/libssl3.so gives and 
that it should list instdir/program/libnss3.so instead of /usr/lib/libnss3.so.
Indeed:
$ ldd instdir/program/libssl3.so 
        libnss3.so => /tmp/build/libreoffice/libreoffice-5.1.2.2/instdir/program/libnss3.so 
(0xb7562000)
        libnssutil3.so => /tmp/build/libreoffice/libreoffice-5.1.2.2/instdir/program/libnssutil3.so 
(0xb7536000)
        libplc4.so => /tmp/build/libreoffice/libreoffice-5.1.2.2/instdir/program/libplc4.so 
(0xb7531000)
        libplds4.so => /tmp/build/libreoffice/libreoffice-5.1.2.2/instdir/program/libplds4.so 
(0xb752c000)
        libnspr4.so => /tmp/build/libreoffice/libreoffice-5.1.2.2/instdir/program/libnspr4.so 
(0xb74e3000)
        libpthread.so.0 => /lib/libpthread.so.0 (0xb748e000)
        libdl.so.2 => /lib/libdl.so.2 (0xb7489000)
        libc.so.6 => /lib/libc.so.6 (0xb72fe000)
        libz.so.1 => /usr/lib/libz.so.1 (0xb72e7000)
        librt.so.1 => /lib/librt.so.1 (0xb72de000)
        /lib/ld-linux.so.2 (0xb76f9000)

So, yeah I guess that upgrading the libnss3 version installed on my system is not necessary because 
the one used here seems to be the version provided by libreoffice.

Any idea what could be the problem?

Thank you.
Best regards.

[1] https://bugs.documentfoundation.org/show_bug.cgi?id=99832