clean: fixes for appveyor warnings

lib/libwebsockets.h

@@ -4066,7 +4066,7 @@ typedef union {
 * parent may be NULL, if given it should be an existing wsi that will become the
 * parent of the new wsi created by this call.
 */
-LWS_VISIBLE struct lws *
+LWS_VISIBLE LWS_EXTERN struct lws *
 lws_adopt_descriptor_vhost(struct lws_vhost *vh, lws_adoption_type type,
 			   lws_sock_file_fd_type fd, const char *vh_prot_name,
 			   struct lws *parent);

lib/server-handshake.c

@@ -156,7 +156,7 @@ lws_extension_server_handshake(struct lws *wsi, char **p, int budget)
 					  LWS_EXT_CB_CONSTRUCT,
 					  (void *)&wsi->act_ext_user[
 					                    wsi->count_act_ext],
-					  &opts, 0)) {
+					  (void *)&opts, 0)) {
 				lwsl_notice("ext %s failed construction\n",
 					    ext_name);
 				ext_count--;

plugins/protocol_lws_server_status.c

@@ -23,6 +23,7 @@
 #include "../lib/libwebsockets.h"
 #include <string.h>
 #include <stdlib.h>
+#include <fcntl.h>
 
 struct lws_ss_load_sample {
 	time_t t;