SmrSector: make clearCache more complete
SmrSector: make clearCache more complete

This method was not clearing all the caches owned by SmrSector.
We now also clear the `CACHE_LOCATION_SECTORS` cache for
completeness (even though it is only used in one obscure place).

smrealms/smr,smrealms/smr,smrealms/smr,hemberger/smr,hemberger/smr,hemberger/smr,hemberger/smr