Balancer tests have been flaky since last balancer rewrite.
Should be from slow balancer failover. Once we re-rewrite balancer
with roundrobin, there should be no more flaky tests as below:
TestBalancerUnderServerStopInflightLinearizableGetOnRestart (27.62s)
server_shutdown_test.go:343: context deadline exceeded
TestBalancerUnderServerShutdownDelete (3.22s)
util.go:32: context deadline exceeded
Signed-off-by: Gyuho Lee <gyuhox@gmail.com>
RPC should be sent to trigger 'readyWait' on new pin address.
Otherwise, endpoints other than ep[0] may be pinned.
Signed-off-by: Gyu-Ho Lee <gyuhox@gmail.com>