Bug - CKEDITOR is not defined when CKEDITOR is disabled and window too small when loading Text Template.

[VeldoraTheDragon]

Environment

• Server OS: FreeBSD 13.3
• Browser: Brave 1.70.119
• Znuny version: 6.5.6

Expected behavior

When loading a Text Template in the Communication -> Note while the RichTextEditor is disabled and the screen is extremly small, the template should still load, without even bothering, if CKEDITOR is disabled or not.

Actual behavior

When loading a Text Template in the Communication -> Note while the RichTextEditor is disabled and the screen is extremely small, the TextArea doesn't update and the loading-circle is circling forever, saying in the browser-console, that CKEDITOR is not defined.

CommonJS_1fb76dcb19b7ee7c1c67869ef1461b2b.js:1648 Uncaught ReferenceError: CKEDITOR is not defined
    at UpdateTextarea (CommonJS_1fb76dcb19b7ee7c1c67869ef1461b2b.js:1648:377)
    at String.<anonymous> (CommonJS_1fb76dcb19b7ee7c1c67869ef1461b2b.js:1662:29)
    at Function.each (CommonJS_1fb76dcb19b7ee7c1c67869ef1461b2b.js:1:3179)
    at UpdateFormElements (CommonJS_1fb76dcb19b7ee7c1c67869ef1461b2b.js:1657:3)
    at Object.success (CommonJS_1fb76dcb19b7ee7c1c67869ef1461b2b.js:1674:6)
    at c (CommonJS_1fb76dcb19b7ee7c1c67869ef1461b2b.js:1:25266)
    at Object.fireWith [as resolveWith] (CommonJS_1fb76dcb19b7ee7c1c67869ef1461b2b.js:1:26015)
    at l (CommonJS_1fb76dcb19b7ee7c1c67869ef1461b2b.js:1:77721)
    at XMLHttpRequest.<anonymous> (CommonJS_1fb76dcb19b7ee7c1c67869ef1461b2b.js:1:80204)

I've pinned down the relevant code that's causing the issue.

Znuny/var/httpd/htdocs/js/Core.AJAX.js

Lines 265 to 267 in c2b68ff

	if (Core.App.Responsive.IsSmallerOrEqual(Core.App.Responsive.GetScreenSize(), 'ScreenL') && (!localStorage.getItem("DesktopMode") || parseInt(localStorage.getItem("DesktopMode"), 10) <= 0)) {
	CKEditorObj = CKEDITOR;
	}

Is there a way to somehow implement a check, if CKEDITOR is defined, instead of assuming that it isn't disabled?
I guess this would already bypass the issue.

How to reproduce

Steps to reproduce the behavior:

1. Disable the RichTextEditor
2. Open a Queue with asigned Text Templates
3. Open a Ticket in this Queue
4. Open Communication -> Note
5. Resize the pop-up window to very small
6. Load the Text-Template
7. See error in browser-console.