merged fix from RC_0_16

ChangeLog

@@ -21,6 +21,8 @@
 	* fix uTP edge case where udp socket buffer fills up
 	* fix nagle implementation in uTP
 
+	* fix issue where torrents added by URL would not be started immediately
+
 0.16.10 release
 
 	* fix encryption level handle invalid values

src/torrent.cpp

@@ -7555,6 +7555,13 @@ namespace libtorrent
 		{
 #if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING
 			debug_log("start_announcing(), files not checked (with valid metadata)");
+#endif
+			return;
+		}
+		if (!m_torrent_file->is_valid() && !m_url.empty())
+		{
+#if defined TORRENT_VERBOSE_LOGGING || defined TORRENT_LOGGING
+			debug_log("start_announcing(), downloading URL");
 #endif
 			return;
 		}