fix libdir in installation
This is part of series of PRs from Debian fixes (see https://anonscm.debian.org/cgit/debian-science/packages/gmsh.git/tree/debian/patches).
This patch fixes the libdir path in when installation gmsh.
This is part of series of PRs from Debian fixes (see https://anonscm.debian.org/cgit/debian-science/packages/gmsh.git/tree/debian/patches).
This patch fixes the libdir path in when installation gmsh.