解决8.0.30+使用cahcing_sha2_password时Fastauth报错问题 (#5406)

Co-authored-by: zhangkai <zhangkai02@xgd.com>

driver/src/main/java/com/alibaba/otter/canal/parse/driver/mysql/MysqlConnector.java

@@ -317,6 +317,9 @@ public class MysqlConnector {
                             // fixed issue https://github.com/alibaba/canal/pull/4767, support mysql 8.0.30+
                             header = cachingSha2PasswordFullAuth(channel, header, getPassword().getBytes(), scramble);
                             body = PacketManager.readBytes(channel, header.getPacketBodyLength(), timeout);
+                        } else {
+                            header = PacketManager.readHeader(channel, 4);
+                            body = PacketManager.readBytes(channel, header.getPacketBodyLength(), timeout);
                         }
                     }
                 } else {