removing tcp_retries

The same data are graphed by the netstat_multi plugin in munin trunk,
so no need to have a redundant plugin.

plugins/network/tcp_retries

@@ -1,45 +0,0 @@
-#!/bin/sh
-
-# tcp_retries revision 2 (Feb 2012)
-#
-# TCP retransmission rate. Useful for network debugging.
-#
-# Required privileges: none
-#
-# OS: Linux with procfs
-#
-# Author: Artem Sheremet <dot.doom@gmail.com>
-#
-
-#%# family=auto
-#%# capabilities=autoconf
-
-TCPSTAT=/proc/net/tcp
-
-case $1 in
-	autoconf)
-		[ -r $TCPSTAT -o -r ${TCPSTAT}6 ] && echo "yes" || echo "no"
-		;;
-    config)
-		cat <<CONFIG
-graph_title TCP retransmissions
-graph_vlabel Rate, retrs/sockets
-graph_category network
-graph_info TCP sockets retransmission counters from $TCPSTAT
-rate.label Retransmission rate
-rate.draw LINE2
-rate.min 0
-CONFIG
-		;;
-esac
-
-cat /proc/net/tcp* | awk '
-{
-	TOTAL += $7;
-	COUNT++;
-}
-
-END {
-	printf "rate.value %.3f\n", TOTAL/COUNT
-}
-'