res_ari_events: Add module reference when a WebSocket is open.

This change ensures that the module isn't unloaded when a
WebSocket is open. Previously it was possible to unload the
module manually or during shutdown which could cause a crash
when any active WebSockets were terminated.

ASTERISK-28585

Change-Id: I85c71ab112f99875b586419a34c08c8b34c14c5c

rest-api-templates/res_ari_resource.c.mustache

@@ -211,6 +211,8 @@ static void ast_ari_{{c_name}}_{{c_nickname}}_ws_established_cb(struct ast_webso
 	struct ast_variable *path_vars = NULL;
 {{/has_path_parameters}}
 
+	SCOPED_MODULE_USE(ast_module_info->self);
+
 {{#has_parameters}}
 	response = ast_calloc(1, sizeof(*response));
 	if (!response) {