unable to delete dotted named theme

[Martronic-SA]

If you add an theme with a zip that has a dotted name, you are not able to delete it.
for example in case of my.custom.theme.zip,
the problem is that the id of the delete modal window becomes "modal-delete-my.custom.theme" and then the $('#modal-delete-my.custom.theme') is not able to find the window.
Possible fix : convert the name my.custom.theme to my_custom_theme