etcdserver/api: add 3.3.0 as compatible server capability

Signed-off-by: Gyuho Lee <gyuhox@gmail.com>

etcdserver/api/capability.go

@@ -37,6 +37,7 @@ var (
 		"3.0.0": {AuthCapability: true, V3rpcCapability: true},
 		"3.1.0": {AuthCapability: true, V3rpcCapability: true},
 		"3.2.0": {AuthCapability: true, V3rpcCapability: true},
+		"3.3.0": {AuthCapability: true, V3rpcCapability: true},
 	}
 
 	enableMapMu sync.RWMutex