Update make-collectd-graphs.sh
Update make-collectd-graphs.sh

Standardise graph image sizes and center all legends
jprochazka/adsb-receiver,jprochazka/adsb-receiver,jprochazka/adsb-feeder,jprochazka/adsb-receiver,jprochazka/adsb-feeder,jprochazka/adsb-receiver,jprochazka/adsb-feeder,jprochazka/adsb-feeder,jprochazka/adsb-receiver,jprochazka/adsb-feeder