Dup before modifying

Because `remove_resource` modifies @my_resources, we can't call it while
iterating over the actual @my_resources. The following snippet
illustrates why:

```
>> a = [1,2,3,4]; a.each {|elem| a.delete(elem); puts elem }
1
3
=> [2, 4]
```

[See rapid7#2002]

Author: egypt

lib/msf/core/exploit/http/server.rb

@@ -230,7 +230,8 @@ def hardcoded_uripath(uri)
 
 	# Take care of removing any resources that we created
 	def cleanup
-		@my_resources.each do |resource|
+		# Must dup here because remove_resource modifies @my_resources
+		@my_resources.dup.each do |resource|
 			remove_resource(resource)
 		end