general: minor bug fixes

Please take an extra look at "WebSearch: cache fix" (7c58b80). This caused quite some for me during testing, but I'm not sure about the implications of changing the value.
It will fire additional query(-ies) in `RestrictedCollectionDataCacher` but I guess we can live with it. In the future we could use Flask-Cache/Redis as a shared memory for checking if the update is necessary.