Improve text instructions

templates/accounts/login_webauthn.html

@@ -21,8 +21,7 @@
     <div id="waiting" class="hide">
         <h2>Waiting for security key</h2>
         <p>
-            Follow your browser's steps to register your security key
-            with {% site_name %}.
+            Follow your browser's steps to authenticate with your security key.
         </p>
 
         <div class="spinner started">