remove spaces in var assignments in system-update.sh
remove spaces in var assignments in system-update.sh

bearing/dosenet-raspberrypi,tybtab/dosenet-raspberrypi,tybtab/dosenet-raspberrypi,cllamb0/dosenet-raspberrypi,yarocoder/dosenet-raspberrypi,cllamb0/dosenet-raspberrypi,yarocoder/dosenet-raspberrypi,bearing/dosenet-raspberrypi