Rever unintencial change

Author: Moser-ss

github/resource_github_repository_ruleset.go

@@ -104,7 +104,7 @@ func resourceGithubRepositoryRuleset() *schema.Resource {
 					Schema: map[string]*schema.Schema{
 						"ref_name": {
 							Type:     schema.TypeList,
-							Optional: true,
+							Required: true,
 							MaxItems: 1,
 							Elem: &schema.Resource{
 								Schema: map[string]*schema.Schema{