error generate in standalone mode

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

util.go

@@ -968,8 +968,10 @@ func (g *Generator) writeErrors(plugin *protogen.Plugin) error {
 	}
 
 	var gfile *protogen.GeneratedFile
+	var importPath protogen.GoImportPath
+
 	if len(errorsMap) > 0 {
-		gfile = plugin.NewGeneratedFile("micro_errors.pb.go", ".")
+
 		var packageName string
 
 		for _, file := range plugin.Files {
@@ -980,9 +982,16 @@ func (g *Generator) writeErrors(plugin *protogen.Plugin) error {
 				continue
 			}
 			packageName = string(file.GoPackageName)
+			importPath = file.GoImportPath
 			break
 		}
 
+		if g.standalone {
+			importPath = "."
+		}
+
+		gfile = plugin.NewGeneratedFile("micro_errors.pb.go", importPath)
+
 		gfile.P("// Code generated by protoc-gen-go-micro. DO NOT EDIT.")
 		gfile.P("// protoc-gen-go-micro version: " + versionComment)
 		gfile.P()