strip modern nib-files correctly when doing release builds

No need to backport this, as 1.0-bugfix only includes classic nibs

Makefile.am

@@ -588,6 +588,7 @@ VLC-release.app: vlc
 	printf "APPLVLC#" >| $(top_builddir)/VLC-release.app/Contents/PkgInfo
 	find $(top_builddir)/VLC-release.app/Contents/Resources/English.lproj -name classes.nib -delete;
 	find $(top_builddir)/VLC-release.app/Contents/Resources/English.lproj -name info.nib -delete;
+	find $(top_builddir)/VLC-release.app/Contents/Resources/English.lproj -name designable.nib -delete;
 	find $(top_builddir)/VLC-release.app -type d -exec chmod ugo+rx '{}' \;
 	find $(top_builddir)/VLC-release.app -type f -exec chmod ugo+r '{}' \;