Revert "Do not try to compile mozilla plugin for win32."

This reverts commit b21ac035.

Commit cc59f655 fixes building for win32.

extras/package/win32/configure-common.sh

@@ -23,6 +23,7 @@
       --enable-portaudio \
       --enable-sdl --with-sdl-config-path=/usr/win32/bin \
       --enable-qt4 \
+      --enable-mozilla --with-mozilla-sdk-path=/usr/win32/gecko-sdk \
       --enable-activex \
       --enable-sse --enable-mmx \
       --enable-libcddb \