[VOL-4291] OfAgent changes for gRPC migration

Change-Id: I8da1db6df49d478ef24ec8f9bd719e9692f48a7f
diff --git a/vendor/go.uber.org/zap/zapcore/write_syncer.go b/vendor/go.uber.org/zap/zapcore/write_syncer.go
index 209e25f..d4a1af3 100644
--- a/vendor/go.uber.org/zap/zapcore/write_syncer.go
+++ b/vendor/go.uber.org/zap/zapcore/write_syncer.go
@@ -91,8 +91,7 @@
 	if len(ws) == 1 {
 		return ws[0]
 	}
-	// Copy to protect against https://github.com/golang/go/issues/7809
-	return multiWriteSyncer(append([]WriteSyncer(nil), ws...))
+	return multiWriteSyncer(ws)
 }
 
 // See https://golang.org/src/io/multi.go