Make pkgconfig_generate() fills Libs with the required linking flags

if the "shared" var has not been explicitely enabled, rather than if
it has been explicitely disabled.

This way is not necessary to explicitely disable shared libraries in
order to have a pc file usable with only static libraries.


git-svn-id: file:///var/local/repositories/ffmpeg/trunk@19868 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

configure

@@ -2796,10 +2796,10 @@ includedir=$incdir
 Name: $name
 Description: $comment
 Version: $version
-Requires: $(disabled shared && echo $requires)
+Requires: $(enabled shared || echo $requires)
 Requires.private: $(enabled shared && echo $requires)
 Conflicts:
-Libs: -L\${libdir} -l${shortname} $(disabled shared && echo $libs)
+Libs: -L\${libdir} -l${shortname} $(enabled shared || echo $libs)
 Libs.private: $(enabled shared && echo $libs)
 Cflags: -I\${includedir}
 EOF