Turris antenna board spacer

There is little machanical problem with antenna boards on Turris Omnia router (https://www.turris.cz/en/). It is difficult to tighten the bolt on antenna connectors as the board has tendency to turn inside the box.

That's why I created this simple spacer.
Not only it helps to tighten the bolts without any problems, but also shortens a bit the outgoing connector thread, so the antennas are little bit less sticked out from the box.