Removed unnecessary setting from the "Create DMG" target

Xcode/SDL/SDL.xcodeproj/project.pbxproj

@@ -2699,7 +2699,6 @@
 		F3676F5A2A7885080091160D /* Debug */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
-				CODE_SIGN_STYLE = Automatic;
 				PRODUCT_NAME = "$(TARGET_NAME)";
 			};
 			name = Debug;
@@ -2707,7 +2706,6 @@
 		F3676F5B2A7885080091160D /* Release */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
-				CODE_SIGN_STYLE = Automatic;
 				PRODUCT_NAME = "$(TARGET_NAME)";
 			};
 			name = Release;