Add config setting for API team deletion (#8800)

config/default.json

@@ -62,7 +62,8 @@
         "ExperimentalGroupUnreadChannels": "disabled",
         "ImageProxyType": "",
         "ImageProxyOptions": "",
-        "ImageProxyURL": ""
+        "ImageProxyURL": "",
+        "EnableAPITeamDeletion": false
     },
     "TeamSettings": {
         "SiteName": "Mattermost",