[rancid] Patch for xrancid Extreme x480 - oscillating "show configuration"

[Howard Jones]

Here's a tiny patch to stop spurious diffs on (at least) Extreme x480 
switches. For some reason they sometimes do and sometimes don't show the 
"show configuration" command in the output.

--- xrancid     2015-05-08 16:43:09.001709176 +0100
+++ ../../bin/xrancid   2016-01-18 10:03:56.175776121 +0000
@@ -357,6 +357,14 @@
         /# system name/i && next;
         /# software version/i && next;

+       # if there's a show configuration (sometimes is, sometimes 
isn't, even on one device!)
+       # remove it, and the following line (a blank comment)
+       if (m/^show\sconfiguration/) {
+               <INPUT>;
+               next;
+       }
+
+
         if (/((create|configure) account \S+ \S+) / && $filter_pwds >= 2) {
             ProcessHistory("COMMENTS","keysort","H0","# $1 <key 
removed>\n");
             next;