Fix rollover inconsistencies.

Patch based on patch from Javier Fernández-Sanguino Peña.

Author: Chris Taylor <ctaylor@debian.org>

--- a/README
+++ b/README
@@ -9,7 +9,7 @@ This is a libpcap-based program.  It has
 
 1) It sniffs packets and spools them straight to the disk and can daemonize 
 itself for background packet logging.  By default the file rolls over when 
-1 GB of data is logged.
+2 GB of data is logged.
 
 2) It sniffs packets and rewrites them to a second interface, essentially 
 acting as a soft tap.  It can also do this in daemon mode.
