Fix headers operation in lua_task.

src/lua/lua_task.c

 static gint
 lua_task_get_request_header (lua_State *L)
 {
-	GString *hdr, srch;
+	rspamd_ftok_t *hdr, srch;
 	struct rspamd_task *task = lua_check_task (L, 1);
 	const gchar *s;
 	struct rspamd_lua_text *t;
 	s = luaL_checklstring (L, 2, &len);
 
 	if (s) {
-		srch.str = (gchar *)s;
+		srch.begin = (gchar *)s;
 		srch.len = len;
 
 		hdr = g_hash_table_lookup (task->request_headers, &srch);
 		if (hdr) {
 			t = lua_newuserdata (L, sizeof (*t));
 			rspamd_lua_setclass (L, "rspamd{text}", -1);
-			t->start = hdr->str;
+			t->start = hdr->begin;
 			t->len = hdr->len;
 			t->own = FALSE;
 
 {
 	struct rspamd_task *task = lua_check_task (L, 1);
 	const gchar *s, *v = NULL;
+	rspamd_fstring_t *buf;
 	struct rspamd_lua_text *t;
-	GString *hdr, srch, *new_name;
+	rspamd_ftok_t *hdr, srch, *new_name;
 	gsize len, vlen;
 
 	s = luaL_checklstring (L, 2, &len);
 		}
 
 		if (v != NULL) {
-			srch.str = (gchar *)s;
+			srch.begin = (gchar *)s;
 			srch.len = len;
 
 			hdr = g_hash_table_lookup (task->request_headers, &srch);
 
-			if (hdr) {
+			if (!hdr) {
 				new_name = &srch;
 			}
 			else {
 				/* Not found, need to allocate */
-				new_name = g_string_new_len (srch.str, srch.len);
+				buf = rspamd_fstring_new_init (srch.begin, srch.len);
+				new_name = rspamd_ftok_map (buf);
 			}
-			hdr = g_string_new_len (v, vlen);
+
+			buf = rspamd_fstring_new_init (v, vlen);
+			hdr = rspamd_ftok_map (buf);
 
 			/* This does not destroy key if it exists */
 			g_hash_table_insert (task->request_headers, new_name, hdr);