Bug 1213033 - please make the MFA code field type=numeric

Author: globau

template/en/default/mfa/totp/verify.html.tmpl

@@ -22,7 +22,7 @@
     [% FOREACH field IN postback.fields.keys %]
       <input type="hidden" name="[% field FILTER html %]" value="[% postback.fields.item(field) FILTER html %]">
     [% END %]
-    <input type="text" name="code" id="code"
+    <input type="[% is_mobile_browser ? "number" : "text" %]" name="code" id="code"
            placeholder="123456" maxlength="9" pattern="\d{6,9}" size="10"
            autocomplete="off" required autofocus><br>
     <br>