Small bug found (I think)

[lakeroe]

I've found a small bug resulting in a slightly different behaviour than the original GRBL.
In system.c (line 480) "sys_rt_exec_alarm |= (code);" has to be changed to "sys_rt_exec_alarm = (code);"

@usbcnc
Do you mind making this change and also my other findings (#29, #36, #38) to your GitHub repository ?
Otherwise they are not very useful ...

This still needs some more investigations: #39

Best regards,
lakeroe

[lakeroe]

For your information: #39 is also solved now