controller: Fix advertised_route incremental handler. #1874

Job	Run time
Prepare container	9m 5s
osx clang --disable-ssl	2m 10s
linux rpm fedora	7m 16s
linux clang --disable-ssl	2m 41s
linux gcc --disable-ssl	2m 37s
linux gcc test 601- unstable	7m 6s
linux clang test sanitizers 301-600	11m 11s
linux gcc test 301-600	8m 48s
linux gcc dist-test	3m 9s
linux gcc test -300	10m 8s
linux clang test sanitizers 601- unstable	11m 8s
linux gcc test -ljemalloc -300	10m 34s
linux gcc system-test-dpdk dpdk -100	16m 44s
linux clang test sanitizers -300	13m 10s
linux gcc test -ljemalloc 301-600	8m 56s
linux gcc system-test -100	20m 14s
linux gcc system-test-dpdk dpdk 101- unstable	24m 21s
linux gcc test -ljemalloc 601- unstable	7m 25s
linux clang system-test sanitizers -100	22m 18s
linux gcc system-test-userspace 101- unstable	23m 10s
linux gcc system-test-userspace -100	15m 30s
linux gcc system-test 101- unstable	32m 55s
linux clang system-test sanitizers 101- unstable	35m 30s
linux x86 gcc --disable-ssl	3m 4s
	5h 9m 10s

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