More string changes in Evolution

[Matthew Barnes <mbarnes redhat com>]

Picked off a couple last-minute bugs that required string changes.

Reword the descriptions for "lookup_addressbook" GConf key.
http://bugzilla.gnome.org/show_bug.cgi?id=549970
http://svn.gnome.org/viewvc/evolution?view=revision&revision=36227

Use a less geeky sounding migration message.
http://bugzilla.gnome.org/show_bug.cgi?id=549969
http://svn.gnome.org/viewvc/evolution?view=revision&revision=36228

Matthew Barnes