Soft limit error bug fix.

- Soft limit errors were stuck in a feed hold without notifying the
user why it was in a hold. When resumed, the soft limit error would
kick in. Issue should be fixed to behave as intended. To automatically
hold and issue a soft limit alarm once the machine has come to a stop.

grbl/protocol.c

@@ -389,7 +389,7 @@ void protocol_exec_rt_system()
       // NOTE: Bresenham algorithm variables are still maintained through both the planner and stepper
       // cycle reinitializations. The stepper path should continue exactly as if nothing has happened.   
       // NOTE: EXEC_CYCLE_STOP is set by the stepper subsystem when a cycle or feed hold completes.
-      if (sys.state & (STATE_HOLD | STATE_SAFETY_DOOR)) {
+      if ((sys.state & (STATE_HOLD | STATE_SAFETY_DOOR)) && !(sys.soft_limit)) {
         // Hold complete. Set to indicate ready to resume.  Remain in HOLD or DOOR states until user
         // has issued a resume command or reset.
         plan_cycle_reinitialize();