fix firefox version

Author: tleepa

bucket/firefox.json

@@ -56,8 +56,8 @@
         "profiles"
     ],
     "checkver": {
-        "url": "https://www.mozilla.org/en-US/firefox/notes/",
-        "regex": "<div class=\"c-release-version\">([\\d.]+)</div>"
+        "url": "https://product-details.mozilla.org/1.0/firefox_versions.json",
+        "jsonpath": "$.LATEST_FIREFOX_VERSION"
     },
     "autoupdate": {
         "architecture": {