[Bug 36148] OSD Mutle icon should show a striked out speaker

[j^]

Public bug reported:
https://launchpad.net/malone/bugs/36148

Affects: control-center gnome-control-center (Ubuntu)
       Severity: Normal
       Priority: (none set)
         Status: Unconfirmed

Description:
right now if you press mute key, i.e. on thinkpads an osd icon is shown
of a speaker without notes infront of it. this is not quite obvious, it
would be better to show that speaker with a read line striking it.