Remove sign identity for development builds

Author: ianyh

Amethyst.xcodeproj/project.pbxproj

@@ -1009,7 +1009,7 @@
 				CLANG_ENABLE_MODULES = YES;
 				CODE_SIGN_ENTITLEMENTS = Amethyst/AmethystDebug.entitlements;
 				CODE_SIGN_IDENTITY = "-";
-				"CODE_SIGN_IDENTITY[sdk=macosx*]" = "Apple Development";
+				"CODE_SIGN_IDENTITY[sdk=macosx*]" = "-";
 				CODE_SIGN_STYLE = Automatic;
 				COMBINE_HIDPI_IMAGES = YES;
 				CURRENT_PROJECT_VERSION = 119;