Ensure http_login scanner module saves passwds.

Fixes #6983.  When the auxiliary/scanner/http/http_login module discovers a successful basic auth user+password combination, make sure we properly store the password by specifically telling the credentials gem that the private data we're storing is a :password.

modules/auxiliary/scanner/http/http_login.rb

@@ -181,6 +181,7 @@ class MetasploitModule < Msf::Auxiliary
       case result.status
       when Metasploit::Model::Login::Status::SUCCESSFUL
         print_brute :level => :good, :ip => ip, :msg => "Success: '#{result.credential}'"
+        credential_data[:private_type] = :password
         credential_core = create_credential(credential_data)
         credential_data[:core] = credential_core
         create_credential_login(credential_data)