package/libssh2: fix autoreconf comment

The comment explaining the autoreconf says that we are building from a git
clone - but we are not, currently.  However, the reconf is still needed due
to patches modifying ac files.

This commit corrects the comment.

Signed-off-by: Danomi Manchego <danomimanchego123@gmail.com>
[yann.morin.1998@free.fr: also mention acincludes.m4]
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>