if the upload failed we still need to try to read the server
response otherwise if the failure is not due to a connection problem,
for example the server denied the upload for quota limits, we miss
the response and we cannot use the connection to send other commands
Here is what happen before this patch:
C->S STOR test_file1.dat
S->C 150 Using transfer connection
S->C 550 Could not transfer file: denying write due to space limit
the client does not read the above 550 response and send the next command, so
the response for the STOR response will be readed as response for the next
command
Nicola Murino