[4003] Added iterator missing include

src/lib/util/random/random_number_generator.h

@@ -1,4 +1,4 @@
-// Copyright (C) 2010  Internet Systems Consortium, Inc. ("ISC")
+// Copyright (C) 2010, 2015  Internet Systems Consortium, Inc. ("ISC")
 //
 // Permission to use, copy, modify, and/or distribute this software for any
 // purpose with or without fee is hereby granted, provided that the above
@@ -17,6 +17,7 @@
 
 #include <algorithm>
 #include <cmath>
+#include <iterator>
 #include <numeric>
 #include <vector>