Wrong definition of the macro SSL_set1_sigalgs in ssl.h

Error in the definition of the macro SSL_set1_sigalgs(ctx, slist,
slistlen): the third parameter 'slistlen' not used in the substitution
code; used 'clistlen' instead. As a result of this, compilation error
occurs when any application uses this macro.

Signed-off-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Kurt Roeckx <kurt@openssl.org>