supybot: Remove extraneous sys.stdin.close()

Signed-off-by: James Vega <jamessan@users.sourceforge.net>
(cherry picked from commit 0e22e218f0)

scripts/supybot

@@ -270,7 +270,6 @@ if __name__ == '__main__':
         sys.stdin.close()
         # Closing these two might cause problems; we log writes to them as
         # level WARNING on upkeep.
-        sys.stdin.close()
         sys.stdout.close()
         sys.stderr.close()
         sys.stdout = StringIO.StringIO()