fix: allow alphanumerical backup codes

do not restrict 2FA codes to numbers

themes/perun/privacyidea/LoginForm.php

@@ -108,7 +108,7 @@ if ($this->data['errorCode'] !== null) {
                 <div class="form-group col-sm-12 col-md-6">
                     <label for="otp" class="sr-only"><?php echo $this->t('{privacyidea:privacyidea:otp}'); ?></label>
                     <input id="otp" name="otp" tabindex="1" value="" class="form-control" autocomplete="one-time-code"
-                      type="number" inputmode="numeric" pattern="[0-9]{6,}" required
+                      inputmode="numeric" required
                       placeholder="<?php echo htmlspecialchars($otpHint, ENT_QUOTES); ?>"
                       <?php echo $this->data['noAlternatives'] ? ' autofocus' : '';?> />
                 </div>