Remove NCR flags from Primm and 188 Outpost

[JackTrenton]

I am rolling with a Independent New Vegas ending, so it's kind of immersion breaking to still see NCR flags everywhere. It would be nice to have the flags at Primm and the 188 replaced with the blue Nevada flag, like the one flying at Doc Mitchell's house, to signify their independence. It's kind of poetic since the Courier's journey began there. It would be even better if the NCR soldiers there could be converted into desert rangers to show that they are controlled by Vegas and not NCR.