GNU package glib2 moved

The folder structure for the glib2 package download has changed. They have removed patch level folders and rolled them up to major.minor folder. The OpenWRT toolchain accounts for this with a change to the PKG_SOURCE_URL

In packages/libs/glib2/Makefile, change line 16 to:
PKG_SOURCE_URL:=@GNOME/glib/$(word 1,$(subst ., ,$(PKG_VERSION))).$(word 2,$(subst ., ,$(PKG_VERSION)))
