[PATCH cygport] Allow manpage section .3G, used by OpenGL manpages

[Yaakov Selkowitz]

On Fri, 2020-04-10 at 15:48 +0100, Jon Turney wrote:
> ---
>  lib/src_install.cygpart | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 

LGTM, please merge.

--
Yaakov