[Grbl_Esp32 PR#25] Function was crashing , with ALARM:10 as overflowing array. replaced …

Function was crashing , with ALARM:10 as overflowing array. replaced with larger array + use of snprintf to truncate rather than overflow in the future.

I’ve added Alarm 10 as motor error in my working copy , this caused the above fault.

First attempt at a pull request , won’t be offended if you reject in favour of Luc’s grbl_sendf(..) function