zlib: Update to 1.2.11

Update to 1.2.11 as suggested by upstream
Also add SF as primary source and main site as fallback

Note: SF doesn't carry the 1.2.11 update yet.

Signed-off-by: Daniel Engberg <daniel.engberg.lists@pyret.net>

package/libs/zlib/Makefile

@@ -8,12 +8,12 @@
 include $(TOPDIR)/rules.mk
 
 PKG_NAME:=zlib
-PKG_VERSION:=1.2.10
+PKG_VERSION:=1.2.11
 PKG_RELEASE:=1
 
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.xz
-PKG_SOURCE_URL:=http://www.zlib.net @SF/libpng
-PKG_HASH:=9612bf086047078ce3a1c154fc9052113fc1a2a97234a059da17a6299bd4dd32
+PKG_SOURCE_URL:=@SF/libpng http://www.zlib.net
+PKG_HASH:=4ff941449631ace0d4d203e3483be9dbc9da454084111f97ea0a2114e19bf066
 
 PKG_LICENSE:=Zlib
 PKG_LICENSE_FILES:=README