remove 'commit' ex3 feature not implemented on ext2
remove 'commit' ex3 feature not implemented on ext2

Caused issue with latest RasPi3 firmware. https://openenergymonitor.org/emon/node/12566
emoncms/emoncms,chaveiro/emoncms,emoncms/emoncms,chaveiro/emoncms,jeremypoulter/emoncms,chaveiro/emoncms,inverse/emoncms,jeremypoulter/emoncms,inverse/emoncms,inverse/emoncms,emoncms/emoncms,chaveiro/emoncms,jeremypoulter/emoncms,thaipowertech/emoncms,emoncms/emoncms,inverse/emoncms,jeremypoulter/emoncms,thaipowertech/emoncms,thaipowertech/emoncms,thaipowertech/emoncms,emoncms/emoncms