fix Xcode 10.2 warning about development region
fix Xcode 10.2 warning about development region

use the correct specifier `en` instead of `English`

CocoaLumberjack/CocoaLumberjack,jum/CocoaLumberjack,jum/CocoaLumberjack,sushichop/CocoaLumberjack,jum/CocoaLumberjack,CocoaLumberjack/CocoaLumberjack,CocoaLumberjack/CocoaLumberjack,sushichop/CocoaLumberjack,sushichop/CocoaLumberjack,CocoaLumberjack/CocoaLumberjack,sushichop/CocoaLumberjack,jum/CocoaLumberjack