clear $URANDOM_FH if OS can't open the file handle.
Checking in changes prior to tagging of version 7.02.

Changelog diff is:

diff --git Changes Changes
index 1012c0f..85cc76a 100644
--- Changes
+++ Changes
@@ -2,6 +2,11 @@ Revision history for Perl extension Amon2-Plugin-Web-CSRFDefender

 {{$NEXT}}

+7.02 2014-08-18T04:58:01Z
+
+    [Mostly win32] [bug fix]
+    - Clear file handle if /dev/urandom is not available.
+
 7.01 2014-07-31T21:08:10Z

     - More secure random number generation.