libubox: update to latest version, fixes an uloop use-after-free bug

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

git-svn-id: svn://svn.openwrt.org/openwrt@36914 3c298f89-4303-0410-b956-a3cf2f4a3e73
uci: update to fix excessive reorder delta entry duplication (#13678)

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

git-svn-id: svn://svn.openwrt.org/openwrt@36915 3c298f89-4303-0410-b956-a3cf2f4a3e73
build: clean up stale files from a previous build when installing a package build to the staging dir

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

Backport of r36755

git-svn-id: svn://svn.openwrt.org/openwrt@36916 3c298f89-4303-0410-b956-a3cf2f4a3e73
AA: backport libjson-c, libubox and uci from trunk

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

git-svn-id: svn://svn.openwrt.org/openwrt@36917 3c298f89-4303-0410-b956-a3cf2f4a3e73