Correct the order with which concat fragments of listening services are collected

Correct the order with which concat fragments of listening services are collected. The previous implementation could result to wrong configuration files. 

Example:

Suppose you have two backend members named lxbrf23, lxbrf24 and the listening services: 
-demoservice
-demoservice-mess
-demoservice-mess-it
-demoservice-mess-it-even
-demoservice-mess-it-even-more

The concat fragments will be alphanumerically ordered and will result to a wrong configuration file.