Update link to onionmine

A user reported to frontdesk@:

https://community.torproject.org/onion-services/advanced/vanity-addresses/

link to Onionmine tool has broken link 404 (https://community.torproject.org/onion-services/ecosystem/apps/web/onionmine/)

please fix this

With the MR, I am updating the link to Onionmine i.e. https://onionservices.torproject.org/apps/web/onionmine/

/cc @rhatto

approved this merge request

resolved all threads

assigned to @gus

mentioned in commit b60bc101

merged