reduce sleep after failure time to 1500 seconds

.drone.yml

@@ -175,7 +175,7 @@ steps:
   environment:
     DOMAIN:
       from_secret: DOMAIN
-    TIMEOUT: 3000
+    TIMEOUT: 1500
   commands:
     - timer=0; while [ "$timer" -lt "$TIMEOUT" ]; do nix shell --inputs-from git+https://git.selfprivacy.org/alexoundos/selfprivacy-tests.git nixpkgs#netcat -c nc -zv -w4 "$DOMAIN" 22; echo "$((TIMEOUT - timer)) seconds remain before teardown - login via ssh to shutdown the machine"; ((timer+=10)); sleep 10; done
   when: