Set the DB path as an env var in systemd service files to prevent footgunning

arch/conduwuit.service

@@ -20,6 +20,7 @@ StandardError=journal+console
 
 Environment="CONTINUWUITY_LOG_TO_JOURNALD=true"
 Environment="CONTINUWUITY_JOURNALD_IDENTIFIER=%N"
+Environment="CONTINUWUITY_DATABASE_PATH=/var/lib/conduwuit"
 
 TTYReset=yes
 # uncomment to allow buffer to be cleared every restart