databases/ruby-sequel: update to 5.22.0

=== 5.22.0 (2019-07-01)

* Fix Dataset#multi_insert and #import with return: :primary_key on MSSQL when the dataset has a row_proc (jeremyevans) (#1627)

* Support Dataset#with :materialized option on PostgreSQL 12 for [NOT] MATERIALIZED (jeremyevans)

* Make Database#primary_key_sequence work on tables without serial sequences on PostgreSQL 12 (jeremyevans)

* Support ruby 2.7+ startless ranges in the pg_range extension (jeremyevans)

* Support ruby 2.7+ startless, endless ranges in filters, using an always true condition for them (jeremyevans)

* Support ruby 2.7+ startless ranges in filters, using just a <= or < operator for them (jeremyevans)

(taca)