gRPC migration update

Change-Id: Icdd1a824948fa994cd36bd121c962f5ecf74e3cf
diff --git a/vendor/go.uber.org/zap/encoder.go b/vendor/go.uber.org/zap/encoder.go
index 2e9d3c3..08ed833 100644
--- a/vendor/go.uber.org/zap/encoder.go
+++ b/vendor/go.uber.org/zap/encoder.go
@@ -62,6 +62,10 @@
 }
 
 func newEncoder(name string, encoderConfig zapcore.EncoderConfig) (zapcore.Encoder, error) {
+	if encoderConfig.TimeKey != "" && encoderConfig.EncodeTime == nil {
+		return nil, fmt.Errorf("missing EncodeTime in EncoderConfig")
+	}
+
 	_encoderMutex.RLock()
 	defer _encoderMutex.RUnlock()
 	if name == "" {