From OpenLieroX Wiki
Because Server Side Health has not been accepted well by the community, there's an option to turn it off. It's pretty hidden in beta 3. To disable it run Notepad (or any other editor) and open file My Documents\OpenLieroX\cfg\options.cfg. Make sure you open the file in My Documents, NOT in your OLX folder. After opening it, scroll down and search for the line:
ServerSideHealth = true
To disable Server Side Health, edit the line to:
ServerSideHealth = false
Save the file and run the game. SSH is now turned off.