prep: Initialization should wait instead of exit the servers. (#2872)

- Servers do not exit for invalid credentials instead they print and wait.
- Servers do not exit for version mismatch instead they print and wait.
- Servers do not exit for time differences between nodes they print and wait.

cmd/auth-rpc-client.go

@@ -135,6 +135,10 @@ func (authClient *AuthRPCClient) Login() error {
 	if reply.ServerVersion != Version {
 		return errServerVersionMismatch
 	}
+	curTime := time.Now().UTC()
+	if curTime.Sub(reply.Timestamp) > globalMaxSkewTime {
+		return errServerTimeMismatch
+	}
 	// Set token, time stamp as received from a successful login call.
 	authClient.token = reply.Token
 	authClient.tstamp = reply.Timestamp