More verbose failure messages

modules/exploits/multi/http/mediawiki_thumb.rb

@@ -343,7 +343,11 @@ class Metasploit3 < Msf::Exploit::Remote
     }, 1)
 
     if r
-      print_error("Received response, exploit probably failed.")
+      if r.code == 404 and r.body =~ /not exist/
+        print_error("File: #{file_name} does not exist.")
+      else
+        print_error("Received response #{r.code}, exploit probably failed.")
+      end
     end
   end