Update vms/libssh2_config.h.
Update vms/libssh2_config.h.

VMS does have stdlib.h, gettimeofday(), and OpenSSL.  The latter
is appropriate to hard-wire in the configuration because it's
installed by default as part of the base operating system and
there is currently no libgcrypt port.

libssh2/libssh2,libssh2/libssh2,libssh2/libssh2,libssh2/libssh2