[Gmsh] cgns output support

[simon place]

when i select this build option, ENABLE_CGNS,  and even though the
objects for this seem to be being built, the program reports that it
hasn't been compiled for cgns support.

and in cmake there is this line,

Gmsh has been configured for Linux with the following options: Ann
Blas Chaco DIntegration FlTree Fltk Gmm Jpeg Lapack MathEx Metis
NativeFileChooser Netgen OpenGL Png Tetgen Zlib

which i would have though should include cgns.

is this a know issue, because i've been looking for an hour now and i
cant see what im doing wrong.