CRM-7811 Error on "Please set a location type of Billing" when having translated string "Billing"

When we have translated string of "Billing" location type, we will block by error, and can't access any page of event registration, contribution ... etc. See the patch will solve our problem.

I notice that the "Billing" location type is reserved by default, and people can't modify by website configuration.
But if it should have translated "Billing" string for display of location type.

This will effect all the languages if they try to change the name of Billing in database.