problem with loolwsd ./configure...

Hello.

I'm trying to configure libreoffice for my owncloud server based on RHEL7.2
And I've stuck on https://github.com/LibreOffice/online/tree/master/loolwsd

...
checking Poco/Net/WebSocket.h presence... yes
configure: WARNING: Poco/Net/WebSocket.h: present but cannot be compiled
configure: WARNING: Poco/Net/WebSocket.h:     check for missing prerequisite headers?
configure: WARNING: Poco/Net/WebSocket.h: see the Autoconf documentation
configure: WARNING: Poco/Net/WebSocket.h:     section "Present But Cannot Be Compiled"
configure: WARNING: Poco/Net/WebSocket.h: proceeding with the compiler's result
configure: WARNING:     ## ------------------------------------------------ ##
configure: WARNING:     ## Report this to libreoffice@lists.freedesktop.org ##
configure: WARNING:     ## ------------------------------------------------ ##
checking for Poco/Net/WebSocket.h... no
configure: error: header Poco/Net/WebSocket.h not found, perhaps you want to use 
--with-poco-includes
...

I use command "/opt/git/online/loolwsd/configure --enable-silent-rules 
--with-lokit-path=/opt/git/libreoffice/include --with-lo-path=/opt/git/libreoffice/instdir 
--enable-debug --with-poco-includes=/opt/poco/Net/include -with-poco-libs=/opt/poco/lib".

The latest Poco compiled from http://pocoproject.org/releases/poco-1.7.5/poco-1.7.5-all.tar.gz  to 
/opt/poco/
LibreOffice is compiled from https://www.libreoffice.org/about-us/source-code/ to 
/opt/git/libreoffice

I've got the same issue with poco-*-1.7.4 from 
ftp://fr2.rpmfind.net/linux/sourceforge/k/ke/kenzy/special/C7/x86_64/

Any ideas?

Thank you in advance,
   Maxim Polyakov