Update config/config.go

Co-authored-by: George Robinson <[email protected]>
Signed-off-by: Christoph Maser <[email protected]>

config/config.go

@@ -369,7 +369,7 @@ func (c *Config) UnmarshalYAML(unmarshal func(interface{}) error) error {
 	}
 
 	if c.Global.RocketchatTokenID != nil && len(c.Global.RocketchatTokenIDFile) > 0 {
-		return fmt.Errorf("at most one of rocketchat_token_id & rocketchat_token_id_file must be configured")
+		return errors.New("at most one of rocketchat_token_id & rocketchat_token_id_file must be configured")
 	}
 
 	names := map[string]struct{}{}