Fix incorrect cherry-pick in previous commit.

app.go

@@ -158,7 +158,7 @@ func main() {
 	go func() {
 		refreshFiltersIfNeccessary(false)
 		// Save the updated config
-		err := writeConfig()
+		err := config.write()
 		if err != nil {
 			log.Fatal(err)
 		}
@@ -170,7 +170,7 @@ func main() {
 	}
 
 	// Save the updated config
-	err := writeConfig()
+	err := config.write()
 	if err != nil {
 		log.Fatal(err)
 	}

config.go

@@ -171,7 +171,7 @@ func parseConfig() error {
 }
 
 // Saves configuration to the YAML file and also saves the user filter contents to a file
-func writeConfig() error {
+func (c *configuration) write() error {
 	c.Lock()
 	defer c.Unlock()
 	configFile := filepath.Join(config.ourBinaryDir, config.ourConfigFilename)
@@ -217,7 +217,7 @@ func writeCoreDNSConfig() error {
 }
 
 func writeAllConfigs() error {
-	err := writeConfig()
+	err := config.write()
 	if err != nil {
 		log.Printf("Couldn't write our config: %s", err)
 		return err