Update project localization as recommended by Xcode 10.2

Author: mattrubin

Authenticator.xcodeproj/project.pbxproj

@@ -608,10 +608,11 @@
 			};
 			buildConfigurationList = C01FCF4E08A954540054247B /* Build configuration list for PBXProject "Authenticator" */;
 			compatibilityVersion = "Xcode 3.2";
-			developmentRegion = English;
+			developmentRegion = en;
 			hasScannedForEncodings = 1;
 			knownRegions = (
 				en,
+				Base,
 			);
 			mainGroup = 29B97314FDCFA39411CA2CEA /* CustomTemplate */;
 			projectDirPath = "";