title: NOTICE: The example draw_triangulation_2 requires Qt and will not be compiled
body: <p>I install cgal and qt5 using vcpkg. Then I encountered this problem when try to use qt5.
  <a href="https://i.stack.imgur.com/TFBGR.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/TFBGR.png" alt="enter image description here" /></a></p>
  <p>It seems that cmake has found qt, but CGAL_Qt5_FOUND still returns false and I still got the message: NOTICE: The example draw_triangulation_2 requires Qt and will not be compiled.</p>
  <p>env:
  Operating system (Windows 10/64 bits):
  Compiler: visual studio 2019
  Specific flags used (if any):
  CGAL version: 5.1
  Boost version: 1.72.0</p>
  <p>How can I fix it?</p>