[winswitch] Disable TCP on systemd socket activation

[Michael Cronenworth]

Hi,

I'm using the Xpra 4.x packages from the official Xpra repo on RHEL 8. I'm also 
using the provided systemd socket and service. This enables the listening socket at 
port 14500 to respond to plain TCP and SSL requests. I would like to disable support 
for plain TCP, but I do not see a combination of config options that works with 
socket activation. Am I right or wrong?

Thanks,
Michael