Icedove: Disable Ctrl-Enter, keyboard shortcuts more generally.

[Alexander McLeay <alexander@thecartographers.net>]

Icedove has a feature where if you press Ctrl-Enter, it offers to send the
email. If you press Ctrl-Enter, Enter, it sends the email. Is it possible
to disable this, so pressing Ctrl-Enter does nothing, or at worst enters a
new line into the message? The dialog box saves me from sloppy fingers if
I inadvertently type Ctrl-Enter, but it doesn’t save me from sloppy
fingers if I inadvertently type Ctrl-Enter, Enter.

(Most gtk programs on my computer allow me to reconfigure keyboard
shortcuts simply by pointing at the menu item and pressing the shortcut I
want to assign to that item, or backspace to delete the current
assignment. I know Icedove doesn’t use gtk, but is it possible to easily
change keyboard shortcuts similarly? or at all?)

Thanks!