Decoding issue

[Schrubitteflau]

Hi,

I recently encountered an issue with pymetasploit3 handling some specific characters.

After getting a Meterpreter shell, I uploaded and executed WinPEAS on the compromised computer (module post/multi/manage/upload_exec). In my case, a crash could occur because pymetasploit is trying to decode everything that is received in UTF-8, but some byte sequences aren't valid because they use another encoding.

I opened a PR allowing us to change the encodings that will be used when data is received at runtime.