ucert: update to lastest git HEAD

Update to latest HEAD in order to fix a stack memory corruption issue:

1056e73 Change the sigb buffer to be the same size as the fread

Signed-off-by: Jo-Philipp Wich <jo@mein.io>

package/system/ucert/Makefile

@@ -5,9 +5,9 @@ PKG_RELEASE:=1
 
 PKG_SOURCE_PROTO:=git
 PKG_SOURCE_URL=$(PROJECT_GIT)/project/ucert.git
-PKG_SOURCE_DATE:=2018-08-07
-PKG_SOURCE_VERSION:=63ad591e5983503fefa00ed0488b0bfd74b2a80d
-PKG_MIRROR_HASH:=f400978e754ea9582d6ac9320948e7f1e77be476460bafa2062b207bdfa9a7c7
+PKG_SOURCE_DATE:=2018-08-08
+PKG_SOURCE_VERSION:=1056e730f56adbc6bc77872e2bbd2bbe01512ec9
+PKG_MIRROR_HASH:=59fc4ab5b5cb10c6e9e0899e3ed5de2f57926e980d31c13ddd1662f36cf40cef
 
 CMAKE_INSTALL:=1
 PKG_CHECK_FORMAT_SECURITY:=1