fix template for http to avoid warning

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

templates/{{trimSuffix ".proto" .File.Name}}_micro_http.pb.go.tmpl

@@ -89,7 +89,7 @@ func (c *{{$ServiceName | lowerFirst}}Service) {{.Name}}(ctx context.Context, re
 {{ range $k, $v := (openapiOption .).Responses }}
 // Error method to satisfy error interface
 func (e *{{- (getMessageType $File $v.Schema.JsonSchema.Ref).Name }}) Error() string {
-    return fmt.Sprintf("%v", e)
+    return fmt.Sprintf("%#v", e)
 }
 {{- end }}
 {{- end }}