Minor Fix - Winevent Security

fix https://github.com/Cyb3rWard0g/HELK/issues/75

helk-logstash/pipeline/12-winevent-security-filter.conf

@@ -842,6 +842,13 @@ filter {
         tag_on_exception =>  "_0591_rubyexception"
       }
     }
+    if [target_process_id] {
+      mutate { gsub => [ "target_process_id", "0x", "" ]}
+      ruby {
+        code => "event.set('target_process_id', event.get('target_process_id').to_s.hex)"
+        tag_on_exception =>  "_0591_rubyexception"
+      }
+    }
   }  
 }