Images aren't displayed correctly in CKEditor non-English wikis

Steps to reproduce:

1. Change the wiki's language to German
2. Edit the sandbox page and select the image in the content of the page.

Expected result:

The border around the image wraps the image, the floating menu is displayed below and the move icon is displayed at the top left of the image:

(Screenshot of XWiki 14.9, but the issue started most likely with 14.10.7 and 15.2RC1.)

Actual result:

In Firefox:

In Chrome:

The reason for this is that the selector that was introduced as part of XWIKI-20725 and changed later as part of XWIKI-22008 matches an attribute value that is translated.