Insufficient number of Xs in template 'outline_logXXX' when installing on Open BSD server

When I try to install outline on OpenBSD server I run the following command to install the server:
```
doas bash -c "$(wget -qO- https://raw.githubusercontent.com/Jigsaw-Code/outline-server/master/src/server_manager/install_scripts/install_server.sh)"
```
and I get the following error:
```
mktemp: insufficient number of Xs in template `outline_logXXX'
```
