Revert "Ensure that the path to moc is valid before building with Qt 5."

This reverts commit 240201b1a2ce1519ba9bf45188cddb8248e852fb.
Merge topic 'workaround-usr-move-qt5' into next

c6f2a7a Revert "Ensure that the path to moc is valid before building with Qt 5."
Revert "Make sure we always find the FindQt4.cmake shipped with CMake itself."

This reverts commit 72bd2064748428ae66599fed76ac5921d42c95df.
Merge topic 'fix-build-without-qt4-with-qt5' into next

2fea298 Revert "Make sure we always find the FindQt4.cmake shipped with CMake itself."