Fix CancelPending input causing a crash when a logic_relay fires this to itself

[WereTech]

Check that the input caller is not the logic_relay itself as this will cause I/O issues that will lead to a crash.

[Brain-dawg]

Might be useful to have this print a Warning to let a mapper know they have bad I/O, rather than silently rejecting it.

[WereTech]

Added the warning message. Wasn't sure how to style it though as I just looked through other warning messages and picked whatever seemed ok enough.

[TeamSpen210]

It'd probably be better to see if you can make CancelEvents just ignore the CancelPending input - I think nOutputID would let you uniquely identify the EventQueuePrioritizedEvent_t which matches the inputdata_t.

[WereTech]

I did try to look into adjusting that function, but it seems that CancelPending only belongs to a logic_relay, so I opted into simply changing the function that calls for cancelevents to just not allow the relay to call that on itself instead of changing a function that many other things rely on which could introduce other issues if done incorrectly.

[TeamSpen210]

I was imagining adding an overload, or parameter to the function.