Add -l flag for language

Author: jaapmarcus

web/src/app/WebApp/Installers/Grav/GravSetup.php

@@ -57,7 +57,8 @@ public function install(array $options = null)
 				'-p '.$options['password'],
 				'-e '.$options['email'],
 				'-P a',
-				'-N '.$options['username']
+				'-N '.$options['username'],
+				'-l en'
 			 ], $status);
 		}
 		return ($status -> code === 1);