When deleting a profile, the confirmation dialog shows "Cancel" and
"Delete" buttons. ESC key should do nothing, but in some distributions
like Debian and Ubuntu newt has a downstream patch that enables it (see
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=584098).

In that case, when pressing ESC the return value of the dialog is not
"Cancel" (1) or "Delete" (2), but the "otherwise" value (0). Fix it by
not checking if "Cancel" is pressed. Instead, check if "Delete" was
pressed, and continue deleting only in that case.

Also, fix the doc comment that incorrectly says that the dialog returns
0/1 for the buttons, it is 1/2.