Fix for xembedsniproxy crash due to NULL returned from xcb_image_get()
Summary:
In my environment (Fedora 27, plasma-workspace-5.11.4-1.fc27.x86_64) xembedsniproxy crashes.
This is caused by NULL being returned by xcb_image_get().
This should fix or at least mitigate the problems from bugs:
https://bugs.kde.org/show_bug.cgi?id=355463
https://bugs.kde.org/show_bug.cgi?id=359664
https://bugzilla.redhat.com/show_bug.cgi?id=1497829
Reviewers: Plasma, davidedmundson
Reviewed By: Plasma, davidedmundson
Subscribers: broulik, plasma-devel
Tags: Plasma
Differential Revision: https://phabricator.kde.org/D9732