decrease expected queries in test_election_grouping_with_posts
decrease expected queries in test_election_grouping_with_posts

From https://docs.djangoproject.com/en/2.2/releases/2.0/

assertNumQueries() now ignores connection configuration queries.
Previously, if a test opened a new database connection,
those queries could be included as part of the assertNumQueries().

DemocracyClub/yournextrepresentative,DemocracyClub/yournextrepresentative,DemocracyClub/yournextrepresentative