'config' cannot be renamed

[zimri-leisher]

 F Prime/CMake target 'config' not available to deployment 'x'. 'config' must:
       1. Must be defined somewhere in the F Prime project
       2. Must be defined before 'x' deployment (register_fprime_deployment)
   'config' is undefined, or included via `add_fprime_subdirectory` after `register_fprime_deployment`. in:
      x/CMakeLists.txt

I'm seeing this error when trying to use a custom config directory called fprime_config. It goes away when I rename the dir to config. It seems that we are no longer able to have a custom named config directory?