Delete non-exist branch should return 404 (#36694)

Fix #36682

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Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

routers/web/repo/branch.go

@@ -95,7 +95,7 @@ func DeleteBranchPost(ctx *context.Context) {
 	defer jsonRedirectBranches(ctx)
 	branchName := ctx.FormString("name")
 
-	if err := repo_service.DeleteBranch(ctx, ctx.Doer, ctx.Repo.Repository, ctx.Repo.GitRepo, branchName, nil); err != nil {
+	if err := repo_service.DeleteBranch(ctx, ctx.Doer, ctx.Repo.Repository, ctx.Repo.GitRepo, branchName); err != nil {
 		switch {
 		case git.IsErrBranchNotExist(err):
 			log.Debug("DeleteBranch: Can't delete non existing branch '%s'", branchName)