ubox: update to latest git HEAD

Signed-off-by: John Crispin <john@phrozen.org>

package/system/ubox/Makefile

@@ -1,13 +1,13 @@
 include $(TOPDIR)/rules.mk
 
 PKG_NAME:=ubox
-PKG_VERSION:=2016-06-09
+PKG_VERSION:=2016-07-02
 PKG_RELEASE=$(PKG_SOURCE_VERSION)
 
 PKG_SOURCE_PROTO:=git
 PKG_SOURCE_URL=$(LEDE_GIT)/project/ubox.git
 PKG_SOURCE_SUBDIR:=$(PKG_NAME)-$(PKG_VERSION)
-PKG_SOURCE_VERSION:=fdda69207d1509e0383e3da549f71666b194c40a
+PKG_SOURCE_VERSION:=81c38e8cc3913afcdf5c6916db0376000086b57f
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION)-$(PKG_SOURCE_VERSION).tar.gz
 CMAKE_INSTALL:=1