Description:

If you upgrade to claws-mail 3.7.9-1 (3.7.9-2 doesn't seem to fix this either) from 3.7.8, you'll notice that
if you were using the Notification plugin's popup notifications, they have changed away from
using libnotify. After a little investigation, I discovered that the configure script in
claws-mail-extra now checks for libnotify < 0.7. 3.7.9-1 and 3.7.9-2 patch the source to compile
against libnotify 0.7, but it doesn't make the new adjustment to the configure script. I've attached
a patch that makes the adjustment.

Additional info:
* Version 3.7.9-1
* Dependency Versions:
claws-mail: 3.7.9-1
libnotify: 0.7.1-1.1

Steps to reproduce:

* Install claws-mail and claws-mail-extra-plugins, both version 3.7.9-1
* Start claws-mail
* Enable the notification plugin
* Enable the popup notification plugin
* Wait for an e-mail to come in
* Observe the manual claws-mail popup (instead of libnotify's triggered popup)