Remove master.factorio_directory config

Remove old config entry for the old locale API that was removed with the
introduction of the new export system in 260f976.

lib/config/definitions.js

@@ -23,12 +23,6 @@ MasterGroup.define({
 	type: "string",
 	initial_value: "database",
 });
-MasterGroup.define({
-	name: "factorio_directory",
-	description: "Path to directory to look for factorio installs",
-	type: "string",
-	initial_value: "factorio"
-});
 MasterGroup.define({
 	name: "http_port",
 	title: "HTTP Port",