Load user information once on startup
Summary:
Apparently the seccomp filter can break KUser in certain setups, so load the
info before the sandbox is active.
Test Plan:
Provided a test package to the reporter on the downstream bug
(https://bugzilla.opensuse.org/show_bug.cgi?id=1160995), who reported
success.
Reviewers: Plasma, davidedmundson
Reviewed By: Plasma, davidedmundson
Subscribers: plasma-devel
Tags: Plasma
Differential Revision: https://phabricator.kde.org/D26722