[QA][5.3] local_max_rate option of vsftpd.conf doesn't work as expected.

Issue

• This case asks you about how local_max_rate option of vsftpd.conf should work.

• local_max_rate specified to limit the data transfer rate doesn't work as expected.  We don't really know why.

• If no local_max_rate is specified, the results of "put" and "get" are as follows at 100 MB file.  In both cases, transfer rate is 120 MB/second or less.

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put:
104857600 bytes sent in 0.86 seconds (1.2e+05 Kbytes/s)

get:
104857600 bytes received in 1.4 seconds (7.1e+04 Kbytes/s)
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• Hereby, we expect the following 2 cases (A and B) show the same result as each other.

A) No local_max_rate is specified  (as mentioned above)
B) local_max_rate is 120 MB

• But, the results are different from each other as follows.

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put:
104857600 bytes sent in 2.3 seconds (4.4e+04 Kbytes/s)

get:
104857600 bytes received in 2.6 seconds (4e+04 Kbytes/s)
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• We wonder why local_max_rate option doesn't work as we expect.