userauth: Fix off by one error when reading public key file

After reading the public key from file the size was incorrectly
decremented by one.

This was usually a harmless error as the last character on the public
key file is an unimportant EOL. But if due to some error the public key
file is empty, the public key size becomes (uint)(0 - 1), resulting in
an unrecoverable out of memory error later.

Signed-off-by: Salvador Fandi??o <sfandino-/E1597aS9LQAvxtiuMwx3w@public.gmane.org>
1 file changed