The select button can get the state of an non-active tab in case of asynchronous task

Reproduction step

1. Edit a page
2. Insert an image
3. Leave the default gallery tab for another tab and select an image
4. Click on select

Expected

100% of the time the select button is enabled

Actual

On the rare case where the gallery take more time to load then the selection of an image on the other tab, the gallery scripts disable the select button, making the form non-submitable.