Gracefully handle existing default login roles If multiple databases are created in the same PostgreSQL cluster, existing roles are now properly re-used. This also fixes running database tests on a cluster that already has these roles, which was broken since rev. 5e38667f740c, because it silently fixed a test for existance of roles that failed if proper creation of the role 'sysadmin' failed during setup of the test database.

[Unit]
Description=Gemma Server
After=network.target

[Service]
Type=simple
ExecStart=/home/gemma/gemma/cmd/gemma/gemma -c /home/gemma/gemma.toml
User=gemma
Group=gemma

[Install]
WantedBy=multi-user.target