The protocol parts for these tests do not include QUIT simply because
the error is CURLE_OPERATION_TIMEDOUT (28) which is a generic timeout
error without specificly saying for which connection it concerns, and
for timeouts libcurl marks the control channel as "invalid". As this
test case times out for the data connection it could still use the
control channel.
591 -> FTP multi PORT and 425 on upload
592 -> FTP multi PORT and 421 on upload
593 -> FTP multi PORT upload, no data conn and no transient neg. reply
594 -> FTP multi PORT upload, no data conn and no positive prelim. reply
1206 -> FTP PORT and 425 on download
1207 -> FTP PORT and 421 on download
1208 -> FTP PORT download, no data conn and no transient negative reply
1209 -> FTP PORT download, no data conn and no positive preliminary reply
