fix channelBanks map so Output Update Speed appears correct in gcs

Right now the Output Update Speed in Output config panel appears as

Channel: 1,4   5,8   9-10

This will fix the bank map to appear as

Channel: 1-4   5-8    9-10

No idea if anything else uses this map.

Sorry to bug you with this little stuff all the time, this was bothering me :)