Convert WebNode to use more reliable HTTP Status detection. Add to tests. This site is slow. I sometimes get HTTP 504 errors when testing it.

data.json

@@ -1053,11 +1053,12 @@
     "username_unclaimed": "noonewouldeverusethis7"
   },
   "WebNode": {
-    "errorMsg": "Ztratili jste se?",
-    "errorType": "message",
+    "errorType": "status_code",
     "rank": 16178,
     "url": "https://{}.webnode.cz/",
-    "urlMain": "https://www.webnode.cz/"
+    "urlMain": "https://www.webnode.cz/",
+    "username_claimed":   "radkabalcarova",
+    "username_unclaimed": "noonewouldeverusethis7"
   },
   "Wikia": {
     "errorMsg": "does not exist",