Support Binary Directories With Spaces

Summary:
Using quotes around the use of @CMAKE_CURRENT_BINARY_DIR@ fixes issues
when having a working dir with spaces in the name.

Test Plan: Clone RKward into a directory with spaces in the name

Reviewers: tfry

Reviewed By: tfry

Subscribers: RKWard-Devel-list

Differential Revision: https://phabricator.kde.org/D8389