Fix bug when an axis is specified multiple times in G0 or G1.
Fix bug when an axis is specified multiple times in G0 or G1.

ambrop72/aprinter,ambrop72/aprinter,fixator/aprinter,fixator/aprinter,ambrop72/aprinter,johnkingsley/aprinter,ambrop72/aprinter,fixator/aprinter,fixator/aprinter,johnkingsley/aprinter,johnkingsley/aprinter,johnkingsley/aprinter,ambrop72/aprinter,johnkingsley/aprinter,fixator/aprinter,ambrop72/aprinter,johnkingsley/aprinter,fixator/aprinter,ambrop72/aprinter,johnkingsley/aprinter