Merge branch 'import_postgres_user' into 'master'

Import the database as the `git` user

See merge request !762

doc/update/mysql_to_postgresql.md

@@ -15,7 +15,9 @@ git clone https://github.com/gitlabhq/mysql-postgresql-converter.git
 cd mysql-postgresql-converter
 mysqldump --compatible=postgresql --default-character-set=utf8 -r databasename.mysql -u root gitlabhq_production
 python db_converter.py databasename.mysql databasename.psql
-psql -f databasename.psql -d gitlabhq_production
+
+# Import the database dump as the application database user
+sudo -u git psql -f databasename.psql -d gitlabhq_production
 
 # Rebuild indexes (see below)