Fixed some glade warnings

Warnings issued previously:

"libglade-WARNING **: unknown attribute `swapped' for <signal>."

This thread suggests that the "swapped" attribute is some legacy
property and can be removed.

http://stackoverflow.com/questions/7827310/how-do-i-fix-the-unknown-attribute-swapped-warnings-from-libglade

This appaerently gets rid of the warning without any side effects