libxml2: upgrade to 2.9.3

Beside some improvements, this also fixes several CVEs, for full
list see upstream changelog at:
https://mail.gnome.org/archives/xml/2015-November/msg00012.html

The patch needed for musl was accepted upstream, so we can remove it.

Signed-off-by: Michael Heimpold <mhei@heimpold.de>

libs/libxml2/Makefile

@@ -1,5 +1,5 @@
 #
-# Copyright (C) 2006-2014 OpenWrt.org
+# Copyright (C) 2006-2015 OpenWrt.org
 #
 # This is free software, licensed under the GNU General Public License v2.
 # See /LICENSE for more information.
@@ -8,14 +8,14 @@
 include $(TOPDIR)/rules.mk
 
 PKG_NAME:=libxml2
-PKG_VERSION:=2.9.2
-PKG_RELEASE:=3
+PKG_VERSION:=2.9.3
+PKG_RELEASE:=1
 
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.gz
 PKG_SOURCE_URL:=http://gd.tuwien.ac.at/languages/libxml/ \
 	http://xmlsoft.org/sources/ \
 	ftp://fr.rpmfind.net/pub/libxml/
-PKG_MD5SUM:=9e6a9aca9d155737868b3dc5fd82f788
+PKG_MD5SUM:=daece17e045f1c107610e137ab50c179
 
 PKG_LICENSE:=MIT
 PKG_LICENSE_FILES:=COPYING