rpcd: Update to 2016-12-03

Brings in the following changes:

0577cfc1acdb cmake: Find libubox/blobmsg_json.h
26c98ec94d7a sys: Check return values of chdir and write
f4089654a399 cmake: Find libubus.h

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>

package/system/rpcd/Makefile

@@ -12,10 +12,10 @@ PKG_RELEASE:=1
 
 PKG_SOURCE_PROTO:=git
 PKG_SOURCE_URL=$(LEDE_GIT)/project/rpcd.git
-PKG_SOURCE_DATE:=2016-06-30
-PKG_SOURCE_VERSION:=23417e94d25570e6d62542bac46edd51e8e0243a
+PKG_SOURCE_DATE:=2016-12-03
+PKG_SOURCE_VERSION:=0577cfc1acdbaf30c31090e75045ba58d6dd8a78
 PKG_MAINTAINER:=Jo-Philipp Wich <jo@mein.io>
-PKG_MIRROR_HASH:=67a12a8a367ff83cd7c16b905e22fee00b0c05ce744189aff1759b85453510bb
+PKG_MIRROR_HASH:=bbcd750df4867a57604e3b922e28f7a019cf940c3586d813d88001dc314e2a1c
 
 PKG_LICENSE:=ISC
 PKG_LICENSE_FILES:=