Update countly.json

public/v2/apps/countly.json

@@ -24,7 +24,7 @@
             "id": "$$cap_countly_version",
             "label": "What version/tag do you want?",
             "description": "Go here to see all versions https://hub.docker.com/r/countly/countly-server/tags",
-            "defaultValue": "latest",
+            "defaultValue": "19.08.1",
             "validRegex": "/^([^\\s^\\/])+$/"
         }
     ]