avahi: gtk support needs libglade as well

package/avahi/avahi.mk

@@ -115,8 +115,8 @@ else
 AVAHI_CONF_OPT += --disable-glib --disable-gobject
 endif
 
-ifeq ($(BR2_PACKAGE_LIBGTK2),y)
-AVAHI_DEPENDENCIES += libgtk2
+ifeq ($(BR2_PACKAGE_LIBGLADE),y)
+AVAHI_DEPENDENCIES += libglade
 else
 AVAHI_CONF_OPT += --disable-gtk
 endif

package/libgtk2/libgtk2.mk

@@ -152,7 +152,6 @@ $(STAMP_DIR)/host_libgtk2_configured: $(STAMP_DIR)/host_libgtk2_unpacked $(STAMP
 		--disable-static \
 		--disable-glibtest \
 		--without-libtiff \
-		--without-libpng \
 		--without-libjpeg \
 		--with-x \
 		--with-gdktarget=x11 \