Investigate warning during the run of the icon integration tests

Introduced in PR #143 

```
Warning: [submission of calculation 34] Unable to copy remote resource from ICON/ECHAM6_CldOptProps.nc to ECHAM6_CldOptProps.nc! NOT Stopping but just ignoring!.
Warning: [submission of calculation 34] Unable to copy remote resource from ICON/dmin_wetgrowth_lookup.nc to dmin_wetgrowth_lookup.nc! NOT Stopping but just ignoring!.
```