Add ability to connect to PostgreSQL via unix socket

config-example.yaml

@@ -116,6 +116,9 @@ db_path: /var/lib/headscale/db.sqlite
 # # Postgres config
 # db_type: postgres
 # db_host: localhost
+
+# This should be set when using a TCP connection, set it to '0' or keep it unset if
+# connecting through a unix socket.
 # db_port: 5432
 # db_name: headscale
 # db_user: foo