Only call dh_set_moduli_file if using OpenSSL.

Fixes link failure when configuring --without-openssl since dh.c is not
linked in.

sshd.c

@@ -1725,8 +1725,10 @@ main(int ac, char **av)
 	parse_server_config(&options, rexeced_flag ? "rexec" : config_file_name,
 	    cfg, &includes, NULL);
 
+#ifdef WITH_OPENSSL
 	if (options.moduli_file != NULL)
 		dh_set_moduli_file(options.moduli_file);
+#endif
 
 	/* Fill in default values for those options not explicitly set. */
 	fill_default_server_options(&options);