Remove unneeded if statements for update repo API (#35140)

just try to make the update func more redable and be more KISS

---
_Sponsored by Kithara Software GmbH_

tests/integration/api_repo_edit_test.go

@@ -53,9 +53,8 @@ func getRepoEditOptionFromRepo(repo *repo_model.Repository) *api.EditRepoOption
 		hasWiki = true
 	} else if unit, err := repo.GetUnit(db.DefaultContext, unit_model.TypeExternalWiki); err == nil {
 		hasWiki = true
-		config := unit.ExternalWikiConfig()
 		externalWiki = &api.ExternalWiki{
-			ExternalWikiURL: config.ExternalWikiURL,
+			ExternalWikiURL: unit.ExternalWikiConfig().ExternalWikiURL,
 		}
 	}
 	defaultBranch := repo.DefaultBranch