xtrans 1.6 will use struct sockaddr_storage if HAVE_STRUCT_SOCKADDR_STORAGE
is defined, even if IPv6 is disabled, unlike previous versions which tied
it to the IPv6 #define.
Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1864>