dialog close bug

[liquidsky1]

Bug recreate steps:

Using LibreJS 7.20.2 in Firefox 91.0.2, and running on Ubuntu 18.04

1. Load a page that encounters a script problem.

2. Click on the " Complain to Site Owner" button.

===> Dialog opens (OK).  In this case, the text "Could not guess any contact page for this site" is displayed (OK).

3. Click the X icon in the upper right corner, to close the dialog.

===> The dialog will not close.  One must backpage in the browser or reload the page to get rid of the dialog.