check whether the result is ok by testing the remote port 22

[tangmingxing1988]

As the new firmware of 4A is not supported yet, and it seems quite sure that it won't be supported anymore as the security issue has been fixed, so it's very important to remind the user strongly, not just put it in the small corner of README. It causes the user in confusion while the result tell them everything goes well but he can't ssh. Maybe we should release a new version, as not everybody read the README very carefully.

[tangmingxing1988]

I have tested it on my router with firmware 2.30.20, it works as expected, printing:

Warning: the process has finished, but it seems that something goes wrong.
* Maybe your firmware version is not supported, is it MiRouter 4A Gigabit 2.30.20 or 3.2.26?
* Anyway you can try it with: telnet miwifi.com

[tangmingxing1988]

@acecilia Does it have any problem?

[tangmingxing1988]

@acecilia Thank you, I have changed some words as you expect, and as far as I know, socket is in the standard library so there is no need to be included in requirements.

[acecilia]

Thanks!