On 10.15, if a user activates secure input of some sort, the hotkey code
will begin to crash inside of any Apple function related to hotkeys,
even after secure input has ended.  This does not appear to be the fault
of OBS; the reason to this is still as of yet unknown, but is suspected
to be a bug inside of Apple code that's a new regression as of 10.15.

So for the time being as a temporary solution to the crash, simply
disable external hotkey support once secure input has been detected.

Because of this issue, the hotkey code should probably be replaced by a
different method of tracking hotkeys, perhaps InstallEventHandler for
example.  This commit is little more than a bandaid to the crash.