Merge topic 'gl2ps-missing-version-check'

1520938b gl2ps: add version check for USE_SYSTEM_GL2PS

Acked-by: Kitware Robot <kwrobot@kitware.com>
Reviewed-by: David Lonie <david.lonie@kitware.com>
Merge-request: !1977

ThirdParty/gl2ps/CMakeLists.txt

-vtk_module_third_party(GL2PS)
+# We require patches merged after version 1.3.9 was released, but no new version
+# is available yet.  The version number here should work once it is released.
+vtk_module_third_party(GL2PS VERSION 1.4.0)