[kde-frameworks/kdelibs4support] Remove workaround.

It's fixed in ECM: ad1406644fb51ee0097095915ffab099718268e0 and/or
f8609e8b64fd9170aa1444ad4e2f6d6d759e9050.

Package-Manager: portage-2.2.10
[kde-frameworks] Remove 5.1.0