Build pgsql connector for Linux release builds

distro-configs/LibreOfficeLinux.conf

 --with-vendor=The Document Foundation
 --with-system-dicts
+--with-system-postgresql
 --without-unix-wrapper
 --without-system-zlib
 --without-system-stdlibs
@@ -35,6 +36,7 @@
 --enable-ext-scripting-beanshell
 --enable-ext-scripting-javascript
 --enable-ext-nlpsolver
+--enable-ext-postgresql-sdbc
 --enable-epm
 --enable-cairo
 --enable-binfilter