[3.4.5] CAN connection drops mid-print (OoM error)

[dc42]

@Diamondback yes when you first print, expect the free memory to go down and then stabilise. It may go down in two sizes of step, one will be 24 (max. 120 steps) and the other will be greater (max. 40 steps). If you do a second print, it should not go down any more.

[Diamondback]

@dc42 After a few consecutive prints without resets, it still sits at 28076. So I guess this is fixed! Awesome work, thanks a lot!