ui: fix wrong string used in a search box (#4258)

Resolves https://codeberg.org/forgejo/forgejo/issues/4256.
Fixes regression caused by https://github.com/go-gitea/gitea/pull/29530/files#diff-b46ae540c8eb41d1ccaa1659489fcc47d72eee4c4f04dc83c5ccf4d6d1a3395eR45.

Preview:
Before - d629f2e9-0d07-4719-9250-52d3ba9f4a9e
After - 6a5f5cb2-124d-4673-a387-8483125a89eb

Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/4258
Reviewed-by: Earl Warren <earl-warren@noreply.codeberg.org>
Reviewed-by: Otto <otto@codeberg.org>

tests/integration/repo_collaborator_test.go

@@ -0,0 +1,37 @@
+// Copyright 2024 The Forgejo Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package integration
+
+import (
+	"net/http"
+	"net/url"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+// TestRepoCollaborators is a test for contents of Collaborators tab in the repo settings
+// It only covers a few elements and can be extended as needed
+func TestRepoCollaborators(t *testing.T) {
+	onGiteaRun(t, func(t *testing.T, u *url.URL) {
+		session := loginUser(t, "user2")
+
+		// Visit Collaborators tab of repo settings
+		response := session.MakeRequest(t, NewRequest(t, "GET", "/user2/repo1/settings/collaboration"), http.StatusOK)
+		page := NewHTMLParser(t, response.Body).Find(".repo-setting-content")
+
+		// Veirfy header
+		assert.EqualValues(t, "Collaborators", strings.TrimSpace(page.Find("h4").Text()))
+
+		// Veirfy button text
+		page = page.Find("#repo-collab-form")
+		assert.EqualValues(t, "Add collaborator", strings.TrimSpace(page.Find("button.primary").Text()))
+
+		// Veirfy placeholder
+		placeholder, exists := page.Find("#search-user-box input").Attr("placeholder")
+		assert.True(t, exists)
+		assert.EqualValues(t, "Search users...", placeholder)
+	})
+}