[CentOS] fix firefox?

[Karanbir Singh]

Paul Bijnens wrote:
>   yum install firefox.i386
> 
> it pulls in xulrunner as well, but two different versions for two different
> architectures (???):

My mistake. I did fix it immediately, but it takes 30 min or so for the 
changes to filter through.

What happened :

the xulrunner and xulrunner-devel multilib pkgset missed the update, and 
the metadata update got run from the script. I realised it immediate and 
reran the script - but by that time the first set of mirrors had already 
done the sync ( it takes about 10 min for the script to run ).

Give it an hour, then try again - it should work as expected.

I've also put in a check to make sure this does not happen again.

- KB