Double hotkey press while holding modifier(s) does not fire

[Harjot1Singh]

Describe the bug https://github.com/ShabadOS/presenter/pull/548#pullrequestreview-516401246

Pressing a hotkey with a modifier, and continuing to hold the modifier while repeating the hotkey causes it to fail and no longer register.

To Reproduce Steps to reproduce the behavior:

1. Press hotkey with modifier, e.g. ctrl+c => Triggers copy
2. Continue holding ctrl
3. Press c again => nothing happens
4. Press ctrl-c => nothing happens furthermore