WebAuthN: Replace sr-only with hidden css-class

src/pretix/control/templates/pretixcontrol/auth/login_2fa.html

@@ -14,7 +14,7 @@
             <input class="form-control" name="token" placeholder="{% trans "Token" %}" autocomplete="one-time-code"
                     type="text" required="required" autofocus="autofocus" id="webauthn-response">
         </div>
-        <div class="sr-only alert alert-danger" id="webauthn-error">
+        <div class="alert alert-danger hidden" id="webauthn-error">
             {% trans "WebAuthn failed. Check that the correct authentication device is correctly plugged in." %}
         </div>
         {% if jsondata %}

src/pretix/control/templates/pretixcontrol/user/2fa_confirm_webauthn.html

@@ -22,7 +22,7 @@
         <button class="btn btn-primary sr-only" type="submit"></button>
     </form>
 
-    <div class="sr-only alert alert-danger" id="webauthn-error">
+    <div class="alert alert-danger hidden" id="webauthn-error">
         {% trans "Device registration failed." %}
     </div>
     <script type="text/json" id="webauthn-enroll">

src/pretix/control/templates/pretixcontrol/user/reauth.html

@@ -18,7 +18,7 @@
         <input class="form-control" id="webauthn-response" name="webauthn"
                 type="hidden">
         {% if jsondata %}
-            <div class="sr-only alert alert-danger" id="webauthn-error">
+            <div class="alert alert-danger hidden" id="webauthn-error">
                 {% trans "WebAuthn failed. Check that the correct authentication device is correctly plugged in." %}
             </div>
             <p><small>