Apple has released its third beta version of iOS 4.1 as well as the accompanying SDK. It remains unclear whether iOS 4.1 addresses the iPhone 4’s proximity sensor issue, however, the release does remove support for Apple’s Game Center social gaming network on the iPhone 3G and 2nd generation iPod Touch, according to Mac Rumors. Both the new iOS 4.1 SDK Beta 2 and pre-release builds are available now for download by paid iPhone developers…