Ilja authored Feb 10, 2020 and Haelwenn committed Feb 10, 2020

* Added "Migrate" to the title because these steps can also be used to migrate the instance to another server
* Added an optional step to reinstall pleroma (esp. for migrating servers)
* Currently the steps threw an error 'could not execute query: ERROR: function "activity_visibility already exists with the same argument types'
   * I added a new step to drop and recreate an empty pleroma-database
   * I played around with the `-c` and `-C` options of pg_restore, but dropping and recreating seemd to be the only way I got it working
   * This was tested on Debian Stretch, psql (PostgreSQL) 9.6.15