Update pulse config to use Ubuntu 14.04 instead of 12.04 (#453)

Simple PR to replace the Ubuntu nodes in use for pulse triggered tests from 12.04 to 14.04. @andreeamatei or @andreieftimie could one of you have a quick look over it?
Why does this line needs to be duplicated? I don't see this in other ondemand ini files.
Might have been an error before? If that's the case we should correct it.