Fix port 0 bug in URIPORT

Author: wvu

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

@@ -476,7 +476,7 @@ def get_uri(cli=self.cli)
       host = "[#{host}]"
     end
 
-    if datastore['URIPORT']
+    if datastore['URIPORT'] != 0
       port = ':' + datastore['URIPORT'].to_s
     elsif (ssl and datastore["SRVPORT"] == 443)
       port = ''