Updated ZDBSP nodebuilder version

Build/Compilers/Nodebuilders/zdbsp.cfg

@@ -26,7 +26,8 @@ nodebuilders
 	{
 		title = "ZDBSP - Normal";
 		compiler = "zdbsp";
-		parameters = "-o%FO %FI";
+		parameters = "-c -o%FO %FI";
+		// -c adds comment indices in UDMF format. This is not documented in the ZDBSP usage.
 	}
 
 	zdbsp_fast