Can't use backspace while speaking because it stops the app.

[deadcoder0904]

Describe the bug
  I only have one trigger command sp option space so I'm thinking I should only use that specific trigger to stop the app but currently when I type backspace because of how it adds an extra space for me (see #158) it completely stops the app and quits the app and transcribes the thing.

To Reproduce
Steps to reproduce the behavior:

1.   Use option space as keyboard shortcut and start talking.
2.   Now start talking and press backspace or delete

Expected behavior
  The backspace should work as is similarly space should work and give space as well.

Desktop (please complete the following information):

• 0.6.9