fixed Quizlet false positive

sherlock/resources/data.json

@@ -1541,10 +1541,11 @@
     "username_unclaimed": "noonewouldeverusethis"
   },
   "Quizlet": {
-    "errorMsg": "Page Unavailable",
+    "errorMsg": "checkUsername\":{\"success\":true",
     "errorType": "message",
     "url": "https://quizlet.com/{}",
     "urlMain": "https://quizlet.com",
+    "urlProbe": "https://quizlet.com/webapi/3.2/users/check-username?username={}",
     "username_claimed": "blue",
     "username_unclaimed": "noonewouldeverusethis"
   },