--disable-ext-pdfimport -> --disable-pdfimport

Sorry, I forgot to announce that 
<http://cgit.freedesktop.org/libreoffice/core/commit/?id=7bf64a5af4088c0f6d4dbf7f493e94fa63e2a4b2> 
"Turn PDF import from bundled extension to plain code" renamed the 
configure switch --disable-ext-pdfimport to --disable-pdfimport.  Please 
adapt your autogen.lastrun files accordingly, esp. on any tinderboxes.

(That commit is part of the plan to turn those extensions that we bundle 
anyway into true, non-extension parts of the core code base.  The 
benefit is that we can get rid of some ugly warts in the code, like 
linking most of basegfx's objects into both the basegfx lib and the 
pdfimport lib from the PDF Import extension, and that LO start-up, esp. 
after version update, becomes less troublesome and potentially faster.)

Stephan