Fix memory leak.

Always perform nexproto callback argument initialisation in s_server
otherwise we use uninitialised data if -nocert is specified.
diff --git a/apps/s_client.c b/apps/s_client.c
index a838362..ef798e8 100644
--- a/apps/s_client.c
+++ b/apps/s_client.c
@@ -1965,6 +1965,10 @@
 			print_stuff(bio_c_out,con,1);
 		SSL_free(con);
 		}
+#if !defined(OPENSSL_NO_TLSEXT) && !defined(OPENSSL_NO_NEXTPROTONEG)
+	if (next_proto.data)
+		OPENSSL_free(next_proto.data);
+#endif
 	if (ctx != NULL) SSL_CTX_free(ctx);
 	if (cert)
 		X509_free(cert);