RaspiVid: Fix typo in help text for network streaming example.
RaspiVid: Fix typo in help text for network streaming example.

s\raspvid\raspivid

kraj/userland,JamesH65/userland,6by9/userland,raspberrypi/userland,kraj/userland,raspberrypi/userland,6by9/userland,6by9/userland,raspberrypi/userland,kraj/userland,JamesH65/userland,JamesH65/userland