Land rapid7#5632, mozilla_reduceright nil fix

Author: MSadek-r7

modules/exploits/windows/browser/mozilla_reduceright.rb

@@ -88,17 +88,21 @@ def junk(n=4)
   def on_request_uri(cli, request)
     agent = request.headers['User-Agent']
     if agent !~ /Firefox\/3\.6\.(16|17)/
-      print_error("This browser is not supported: #{agent.to_s}")
+      print_error("This browser is not supported: #{agent}")
       send_not_found(cli)
       return
     end
 
     my_target = target
     if my_target.name == 'Automatic'
-      if agent =~ /NT 5\.1/ and agent =~ /Firefox\/3\.6\.16/
+      if agent =~ /NT 5\.1/ && agent =~ /Firefox\/3\.6\.16/
         my_target = targets[1]
-      elsif agent =~ /NT 6\.1/ and agent =~ /Firefox\/3\.6\.16/
+      elsif agent =~ /NT 6\.[01]/ && agent =~ /Firefox\/3\.6\.16/
         my_target = targets[2]
+      else
+        print_error("This browser is not a viable target: #{agent}")
+        send_not_found(cli)
+        return
       end
     end