fix: setup-mfa-tpl.php button colors

templates/setup-mfa-tpl.php

@@ -11,12 +11,11 @@ $this->includeAtTemplateBase('includes/header.php');
   <div>
       <p><?php echo $this->t('{authswitcher:mfa:setup_mfa_text}'); ?></p>
       <?php if (!empty($this->data[SwitchAuth::PARAM_MFA_REDIRECT_URL])) { ?>
-        <a class="btn btn-lg btn-primary"
-           href="<?php echo $this->data[SwitchAuth::PARAM_MFA_REDIRECT_URL]; ?>">
-            <span><?php echo $this->t('{authswitcher:mfa:manage_tokens_button}'); ?></span>
-        </a>
+        <form action="<?php echo htmlspecialchars($this->data[SwitchAuth::PARAM_MFA_REDIRECT_URL]); ?>" method="GET">
+          <input type="submit" class="btn btn-lg btn-primary"
+                 value="<?php echo $this->t('{authswitcher:mfa:manage_tokens_button}'); ?>">
+        </form>
       <?php } ?>
-
   </div>
 </div>