[Firefox] Default Ctrl+Shift+E shortcut is in use in Firefox. Change to other combination

[acornestean]

Description:
The default Ctrl+Shift+E shortcut with which the extension comes configured is in use in Firefox to bring up the web console (Network tab).
The default shortcut needs to be changed to an available combination.

Steps to reproduce:

1. Load the Firefox Firefox Bridge v0.1 in the browser
2. The welcome page opens in a new tab. Notice the default Ctrl+Shift+E shortcut listed on the page
3. Access https://www.wikipedia.org/ in a new tab and perform the Ctrl+Shift+E shortcut
4. Notice the web console is brought up instead of opening the page in the selected browser

Expected:
A new default shortcut should be used.

Actual:
The current default Ctrl+Shift+E shortcut opens the web console.