fix: set CMAKE_MACOSX_BUNDLE=YES only if it has not been defined

Author: georgemp

ios.toolchain.cmake

@@ -677,7 +677,9 @@ if(NOT ENABLE_STRICT_TRY_COMPILE_INT)
   set(CMAKE_TRY_COMPILE_TARGET_TYPE STATIC_LIBRARY)
 endif()
 # All iOS/Darwin specific settings - some may be redundant.
-set(CMAKE_MACOSX_BUNDLE YES)
+if (NOT DEFINED CMAKE_MACOSX_BUNDLE)
+  set(CMAKE_MACOSX_BUNDLE YES)
+endif()
 set(CMAKE_XCODE_ATTRIBUTE_CODE_SIGNING_REQUIRED "NO")
 set(CMAKE_SHARED_LIBRARY_PREFIX "lib")
 set(CMAKE_SHARED_LIBRARY_SUFFIX ".dylib")