MINOR: mux-h1: Set error code if possible when MUX_EXIT_STATUS is returned

In h1_ctl(), if output parameter is provided when MUX_EXIT_STATUS is
returned, it is used to set the error code. In addition, any client errors
(4xx), except for 408 ones, are handled as invalid errors
(MUX_ES_INVALID_ERR). This way, it will be possible to customize the parsing
error code for request messages.
1 file changed