[source] zlib: Update to 1.2.11

[LEDE Commits]

jow pushed a commit to source.git, branch master:
https://git.lede-project.org/da5d060ac9171029cfde61ee45aa417696e45da0

commit da5d060ac9171029cfde61ee45aa417696e45da0
Author: Daniel Engberg <daniel.engberg.lists at pyret.net>
AuthorDate: Sun Jan 15 21:46:27 2017 +0100

    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 at pyret.net>
---
 package/libs/zlib/Makefile | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/package/libs/zlib/Makefile b/package/libs/zlib/Makefile
index d6155b6..902381b 100644
--- a/package/libs/zlib/Makefile
+++ b/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