Fix CMakeLists.txt to work with older versions of CMake
Summary: The VERSION_GREATER_EQUAL macro was only introduced with version 3.7, and many distros (including KDE Neon) ship an older version of CMake. This patch restores compatibility with those older versions.
Test Plan: Now I can build Discover again
Reviewers: apol, Discover Software Store
Reviewed By: apol, Discover Software Store
Subscribers: plasma-devel
Tags: Plasma
Differential Revision: https://phabricator.kde.org/D14112