Changes to mobile/region.properties: DO NOT add new keys

[Francesco Lodolo [:flod]]

Hi,
since I've already seen 2 locales adding these keys (and filed 2 bugs to
get them removed): en-US added some keys to mobile/region.properties (
browser.suggestedsites.*).
Please, *do not add* these keys to your locale for now.

I'll send a message to this list as soon as it's clear if we need to add
them, and detailed instructions to do it. For now we're falling back to
en-US values, so no functionality is broken or missing.

As I wrote in the previous message: don't make changes freely to
region.properties files, or files in /searchplugins. There are
productization files, and *any change needs to be approved in a bug
before landing* (or whitelisted here, like the Metro p12n clean-up).

If you see en-US changing or adding some keys, that doesn't mean that
the change is automatically approved. Always check the list of files
you're committing before a commit ("hg status"), don't do mass commits,
that's the best way to make a mess. If you have doubts, please ask.

Francesco