override Ext.Components 'validIdRe' to include '@'

override Ext.Components 'validIdRe' to include '@'

we use itemIds with '@' already in the ceph dashboard, and in
non-debug modeit works (as expected) but throws an error
while using ext-all-debug.js so override it to include the '@'

the regex was in place because in html4 the 'id' tag could only consist
letters ofthe mentioned regex, this was lifted in html5 though[0]

0: https://developer.mozilla.org/en-US/docs/Web/HTML/Global_attributes/id

Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>