Pass LANG environment variable to language server.

The LANG env variable is needed for rufo, so that it is able to parse ruby files with multibyte characters.
Since it should be available and correct in most Mac and Linux environments we only need to pass the host value.

Author: pmk1c

client/src/util/env.ts

@@ -92,6 +92,7 @@ const RUBY_ENVIRONMENT_VARIABLES = [
 	'GEM_ROOT',
 	'HOME',
 	'RUBOCOP_OPTS',
+	'LANG',
 ];
 
 export interface IEnvironment {