feat: improve error message for unknown game server (#4218)

The code changes modify the error message displayed when an unknown game server is entered. The new message now capitalizes the first letter of "unknown" and adds an exit status of 1 to terminate the script.

linuxgsm.sh

@@ -369,7 +369,8 @@ if [ "${shortname}" == "core" ]; then
 		if [ "${userinput}" == "${gameservername}" ] || [ "${userinput}" == "${gamename}" ] || [ "${userinput}" == "${shortname}" ]; then
 			fn_install_file
 		else
-			echo -e "[ FAIL ] unknown game server"
+			echo -e "[ FAIL ] Unknown game server"
+			exit 1
 		fi
 	else
 		fn_install_getopt

tests/tests_fctrserver.sh

@@ -369,7 +369,7 @@ if [ "${shortname}" == "core" ]; then
 		if [ "${userinput}" == "${gameservername}" ] || [ "${userinput}" == "${gamename}" ] || [ "${userinput}" == "${shortname}" ]; then
 			fn_install_file
 		else
-			echo -e "[ FAIL ] unknown game server"
+			echo -e "[ FAIL ] Unknown game server"
 		fi
 	else
 		fn_install_getopt

tests/tests_jc2server.sh

@@ -370,7 +370,7 @@ if [ "${shortname}" == "core" ]; then
 		if [ "${userinput}" == "${gameservername}" ] || [ "${userinput}" == "${gamename}" ] || [ "${userinput}" == "${shortname}" ]; then
 			fn_install_file
 		else
-			echo -e "[ FAIL ] unknown game server"
+			echo -e "[ FAIL ] Unknown game server"
 		fi
 	else
 		fn_install_getopt

tests/tests_mcserver.sh

@@ -370,7 +370,7 @@ if [ "${shortname}" == "core" ]; then
 		if [ "${userinput}" == "${gameservername}" ] || [ "${userinput}" == "${gamename}" ] || [ "${userinput}" == "${shortname}" ]; then
 			fn_install_file
 		else
-			echo -e "[ FAIL ] unknown game server"
+			echo -e "[ FAIL ] Unknown game server"
 		fi
 	else
 		fn_install_getopt

tests/tests_ts3server.sh

@@ -370,7 +370,7 @@ if [ "${shortname}" == "core" ]; then
 		if [ "${userinput}" == "${gameservername}" ] || [ "${userinput}" == "${gamename}" ] || [ "${userinput}" == "${shortname}" ]; then
 			fn_install_file
 		else
-			echo -e "[ FAIL ] unknown game server"
+			echo -e "[ FAIL ] Unknown game server"
 		fi
 	else
 		fn_install_getopt