msfconsole command

resolves rapid7#7330

Warns the user if they try to run msfconsole in msfconsole and does not let them do it

Author: “Brian

lib/msf/ui/console/driver.rb

@@ -638,6 +638,10 @@ def stop
   # executable.  This is only allowed if command passthru has been permitted
   #
   def unknown_command(method, line)
+    if File.basename(method) == 'msfconsole'
+      print_error('msfconsole cannot be run inside msfconsole');
+      return
+    end
 
     [method, method+".exe"].each do |cmd|
       if command_passthru && Rex::FileUtils.find_full_path(cmd)