[Bug 30783] [Dapper] ISO files don't have a custom icon anymore

[Trouilliez vincent]

Public bug reported:
https://launchpad.net/malone/bugs/30783

Affects: nautilus (Ubuntu)
       Severity: Normal
       Priority: (none set)
         Status: Unconfirmed

Description:
ISO files used to have a nice icon of their own, to make them stand out
in Nautilus. But recently I noticed that it's gone, and they only have a
very generic text file-like icon. Kinda a regression.

I think it worked fine with Flight 3, and the problem appeared only once
I had updated it.