Bug 725573 - Adapt to evolution 3.11.91 changes
fix deprecated soup functions

Reference: https://bugzilla.gnome.org/show_bug.cgi?id=720459
Signed-off-by: Igor Gnatenko <i.gnatenko.brain@gmail.com>
Bug 720459 - evolution-rss fail to load with 3.8: Plugin Evolution RSS is missing a function named e_plugin_ui_init()