buildscript: bump openwrt to a03a846c49c067048cd225d476a7adf91ef8ff03

- kernel security fixes
- ar71xx dma bug fixes
- ..

Signed-off-by: Tim Niemeyer <tim.niemeyer@mastersword.de>
Reviewed-by: Christian Dresel <fff@chrisi01.de>

buildscript

@@ -13,7 +13,7 @@
 
 builddir=./build
 
-OPENWRTREV="1cd5709e5d9d6e73eb501f1f2840379aa8d171db"
+OPENWRTREV="a03a846c49c067048cd225d476a7adf91ef8ff03"
 OPENWRTURL="git://git.openwrt.org/15.05/openwrt.git"
 PACKAGEREV="ee0bb7b9df86cec0f1d7c27046c50b1fc45b7c4f"
 PACKAGEURL="https://github.com/openwrt/packages.git"