Update QR.captcha.coffee

added changes from MayhemYDG to solve captcha issue

src/Posting/QR.captcha.coffee

@@ -58,6 +58,8 @@ QR.captcha =
     QR.captcha.nodes.challenge = challenge
     new MutationObserver(QR.captcha.load.bind QR.captcha).observe challenge,
       childList: true
+      subtree: true
+      attributes: true
     QR.captcha.load()
 
   sync: (captchas) ->
@@ -134,4 +136,4 @@ QR.captcha =
       @save()
     else
       return
-    e.preventDefault()
+    e.preventDefault()