Fix for #1359358 dcs_installer server file format

Changed code to generate the new DCS servers file format
of one line per node with a count of servers for that node
instead of the older format of listing a node multiple times

Old format:
node1
node2
node3
node1
node2
node3
node1
node2

New format:
node1 3
node2 3
node3 2

Change-Id: Ice5ba9ced25ea61b6dea23a2f6036605dcd7a694
Merge "Fix for #1359358 dcs_installer server file format"