gnutls.c:943:21: warning: comparison of integer expressions of different signedness...

gnutls.c:943:21: warning: comparison of integer expressions of different signedness: ‘int’ and ‘unsigned int’ [-Wsign-compare]

The gci->nr_certs field is an unsigned int. Use that as the loop variable
for freeing them too. And we don't actually need the if (gci->certs)
condition here either because ->nr_certs won't be non-zero in that case
anyway.

Signed-off-by: Tom Carroll <incentivedesign@gmail.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>