Changed multiline pattern to match the footer

Bremgartner, Lucas · Bremgartner, Lucas · commit 59818379c8d8 · 2015-10-29T10:07:37.000+01:00
Fixes #13
diff --git a/logstash-modsecurity.conf b/logstash-modsecurity.conf
@@ -57,7 +57,7 @@ filter {
   #~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
   multiline {
-    pattern => "^--[a-fA-F0-9]{8}-A--$"
+    pattern => "^--[a-fA-F0-9]{8}-Z--$"
     negate => true
     what => previous
     type => "mod_security"
