Hide negative results behind vprint_error within auxiliary/scanner/ssh/ssh_enumusers

[s1e2b3i4]

If you use the auxiliary/scanner/ssh/ssh_enumusers module and test a lot of users, the output gets polluted with many misses (e.g User 'xxx' not found).
Other auxiliary-moules hide those negative results per default and show them only if you specify verbose output.

My changes change the prints so that they also only show positive results per default. You can still get the full output if verbose is true.

Verification

List the steps needed to make sure this thing works

• Start msfconsole
• use uxiliary/scanner/ssh/ssh_enumusers
• set rhosts <IP>
• set user_file /opt/metasploit-framework/embedded/framework/data/wordlists/unix_users.txt
• run
• Verify that users who are not found are not displayed in the output by default
• set verbose true
• run
• Verify that now all results are displayed

[gwillcox-r7]

This looks good to me. Usually I would also ask one to update the documentation file as well but it seems in this case the user documented running the file with the VERBOSE mode set, so there are no updates that are needed there. The one thing that I did note might need changing is the line vprint_error("#{peer(ip)} User '#{user}' on could not connect") which seems to have an extra on where I believe the IP address was meant to go; this can probably be removed to make the line make more sense seeing as we are making edits to this part of the file.

Will ninja commit in the fixes for that one line but otherwise this is good to merge. Thanks for the PR @s1e2b3i4!

[gwillcox-r7]

Release Notes

Updated auxiliary/scanner/ssh/ssh_enumusers so that error messages which arise when a user doesn't exist on the target system, or whom can't connect remotely, are now only displayed if the VERBOSE flag is set.

[gwillcox-r7]

Thanks again @s1e2b3i4 and congrats on your first MSF PR!

[s1e2b3i4]

Thanks for the fast response and the warm welcome, even if I only changed 2 characters 😅