Better logging when exploit gets 401

modules/exploits/linux/http/f5_icall_cmd.rb

@@ -217,7 +217,7 @@ class Metasploit3 < Msf::Exploit::Remote
     if res && res.code == 500 && res.body =~ /path is empty/
       return Exploit::CheckCode::Appears
     elsif res && res.code == 401
-      print_error('401 Unauthorized')
+      print_warning("HTTP/#{res.proto} #{res.status} #{res.message} -- incorrect USERNAME or PASSWORD?")
       return Exploit::CheckCode::Unknown
     else
       return Exploit::CheckCode::Safe