Mozilla location service is dead, replace references with beaconDb

[pvuorela]

For now just removed telling explicitly how the advanced location settings looks like, and the old screenshot from it. The actual content might depend a bit on the device etc.

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}