[Evolution] Allow URLs in "Location" fields to be clickable

[Paul Smith <paul mad-scientist net>]

Hi all; I filed https://bugzilla.gnome.org/show_bug.cgi?id=790263
requesting that URLs in Calendar Location fields be made clickable. 
These days more and more meetings are happening online and so Location
fields very often have URLs in them; it's a pain to have to copy/paste
them separately into a browser (especially since the Location text in
the Calendar reminder popups isn't selectable at all).

(currently using Evolution 3.26.1 on Ubuntu 17.10)

Cheers!