Update Services_Upgrade_Base.php
Update Services_Upgrade_Base.php

https://github.com/spotweb/spotweb/issues/452

Added option --clear-cache to truncate cache table and emtpy cache folder on-disk.
tswestendorp/spotweb,Spotweb/Spotweb,tswestendorp/spotweb,GeoffreyDijkstra/spotweb,Spotweb/Spotweb,mesa57/spotweb,mesa57/spotweb,GeoffreyDijkstra/spotweb