Use just LF for in terminator

[FreddieAkeroyd]

See ISISComputingGroup/IBEX#7778

[rerpha]

did we have this wrong for all kepcos? can't remember if they were used elsewhere other than the zf system?
edit: jsut remembered the HTS magnet did as well?

[FreddieAkeroyd]

The kepco allows either CR or LF as the terminator for data sent to it, I changed the kepco protocol to send just LF (to save one character - also with CR LF the kepco starts processing at CR and i wasn't sure what would happen to the LF in that case). So this is just to make the emulator consistent with the corresponding PR that changes the kepco proto file. If anything other than the kepco IOC uses the kepco lewis emulator, then it may need changing too.