Kevin Daudt b40646469c community/darktable: disable on x86
Build error saying platform is not supported:

```
-- Performing Test IS_SUPPORTED_PLATFORM
-- Performing Test IS_SUPPORTED_PLATFORM - Failed
CMake Error at ConfigureChecks.cmake:44 (message):
  The target platform is not supported!
Call Stack (most recent call first):
  CMakeLists.txt:60 (include)
```
2019-12-25 22:00:42 +00:00
..
2019-12-25 22:00:42 +00:00