northd: Populate additional-chassis to HA group. #3261

Job	Run time
dpdk gcc	5s
linux rpm fedora	6m 50s
osx clang --disable-ssl	2m 22s
Prepare container	2m 14s
linux gcc --disable-ssl	2m 15s
linux clang --disable-ssl	2m 20s
linux gcc test -500	14m 12s
linux gcc test 501-1000	10m 13s
linux gcc test 1001-	5m 40s
linux clang test sanitizers -300	11m 9s
linux clang test sanitizers 301-600	14m 10s
linux clang test sanitizers 601-900	9m 24s
linux clang test sanitizers 901-1200	7m 35s
linux clang test sanitizers 1201-	7m 17s
linux gcc test -ljemalloc -500	14m 42s
linux gcc test -ljemalloc 501-1000	10m 37s
linux gcc test -ljemalloc 1001-	5m 59s
linux gcc system-test-dpdk dpdk -100	10m 50s
linux gcc system-test-dpdk dpdk 101-200	17m 39s
linux gcc system-test-dpdk dpdk 201-	19m 12s
linux gcc system-test-userspace -100	9m 47s
linux gcc system-test-userspace 101-200	15m 54s
linux gcc system-test-userspace 201-	17m 46s
linux gcc system-test -100	12m 44s
linux gcc system-test 101-200	18m 31s
linux gcc system-test 201-	25m 35s
linux clang system-test sanitizers -100	14m 31s
linux clang system-test sanitizers 101-200	20m 10s
linux clang system-test sanitizers 201-	27m 59s
linux x86 gcc --disable-ssl	2m 15s
	5h 39m 57s

Provide feedback