[BUG] Multi camera support uses wrong port

[Qnerd]

With commit 6aeffb38c11ad48a5d4e7ceda5741fb001d6c887 the first port for mjpg-streamer ist 8081 and not 8080 wich is used in default config.

See COUNTER increment in startup file.

[tkyanko]

It looks like this is fixed in https://github.com/OctoPrint/octoprint-docker/pull/246