Add minor delay to docker reset - Squid KNF

This adds a delay to the docker reset command
so that the action doesn't fail.

This change is for the Squid KNF used in the
Hackfest.
Signed-off-by: Dominik Fleischmann <dominik.fleischmann@canonical.com>

magma/hackfest_squid_cnf/charms/squid/src/charm.py

@@ -110,7 +110,7 @@ class SquidK8SCharm(CharmBase):
 
         if line_deleted:
             event.set_results({"output": "URL deleted succesfully"})
-            subprocess.check_output("kill -HUP `cat /var/run/squid.pid`", shell=True)
+            subprocess.Popen("sleep 1 && kill -HUP `cat /var/run/squid.pid`", shell=True)
         else:
             event.fail("No URL was deleted")