import: add seal option

dashboard/src/views/app.html

@@ -345,6 +345,13 @@
             <input type="number" class="form-control" ng-model="importBackup.mountOptions.port" id="configureBackupPort" name="port" ng-disabled="importBackup.busy" ng-required="importBackup.provider === 'sshfs'">
           </div>
 
+          <!-- CIFS -->
+          <div class="checkbox" ng-show="importBackup.provider === 'cifs'">
+            <label>
+              <input type="checkbox" ng-model="importBackup.mountOptions.seal">{{ 'backups.configureBackupStorage.cifsSealSupport' | tr }}</input>
+            </label>
+          </div>
+
            <!-- CIFS/NFS/SSHFS -->
           <div class="form-group" ng-show="importBackup.provider === 'cifs' || importBackup.provider === 'nfs' || importBackup.provider === 'sshfs'">
             <label class="control-label" for="configureBackupRemoteDir">{{ 'backups.configureBackupStorage.remoteDirectory' | tr }} ({{ importBackup.provider }})</label>