fix: correct and standardise name of goldsrc engine (#2814)

GoldSrc servers were names variants of Gold Source. Using correct engine name GoldSrc

lgsm/functions/install_server_files.sh

@@ -152,7 +152,7 @@ fn_install_server_files_steamcmd(){
 	# GoldSrc (appid 90) servers commonly fail to download all the server files required.
 	# Validating a few of times may reduce the chance of this issue.
 	if [ "${appid}" == "90" ]; then
-  fn_print_information_nl "GoldSrc servers commonly fail to download all the server files required. Validating a few of times may reduce the chance of this issue."
+    fn_print_information_nl "GoldSrc servers commonly fail to download all the server files required. Validating a few of times may reduce the chance of this issue."
 		counter="0"
 		while [ "${counter}" -le "4" ]; do
 			counter=$((counter+1))