[Mattermost] Reduce healthcheck interval

pica-mattermost/Dockerfile

@@ -35,7 +35,7 @@ RUN mkdir -p /mattermost/data /mattermost/plugins /mattermost/client/plugins \
     && setcap cap_net_bind_service=+ep /mattermost/bin/mattermost
 
 #Healthcheck to make sure container is ready
-HEALTHCHECK --interval=5m --timeout=3s CMD curl --fail http://localhost:8000//api/v4/system/ping || exit 1
+HEALTHCHECK --interval=20s --timeout=3s CMD curl --fail http://localhost:8000//api/v4/system/ping || exit 1
 
 # Configure entrypoint and command
 COPY entrypoint.sh /