Add a --settings-ui option for AppSettingsCommand (pterodactyl#1446)

* Add a --settings-ui option for AppSettingsCommand

Sorry if my code is below par, I don't know php. All this does is allow the APP_ENVIRONMENT_ONLY to be set via an option, which as far as I can tell, isn't currently possible. I've tested this on a local installation and it works.

Author: PiggyPiglet

app/Console/Commands/Environment/AppSettingsCommand.php

@@ -68,7 +68,7 @@ class AppSettingsCommand extends Command
                             {--redis-host= : Redis host to use for connections.}
                             {--redis-pass= : Password used to connect to redis.}
                             {--redis-port= : Port to connect to redis over.}
-                            {--disable-settings-ui}';
+                            {--settings-ui= : Enable or disable the settings UI.}';
 
     /**
      * @var array
@@ -138,8 +138,8 @@ public function handle()
             array_key_exists($selected, self::ALLOWED_QUEUE_DRIVERS) ? $selected : null
         );
 
-        if ($this->option('disable-settings-ui')) {
-            $this->variables['APP_ENVIRONMENT_ONLY'] = 'true';
+        if (! is_null($this->option('settings-ui'))) {
+            $this->variables['APP_ENVIRONMENT_ONLY'] = $this->option('settings-ui') == 'true' ? 'false' : 'true';
         } else {
             $this->variables['APP_ENVIRONMENT_ONLY'] = $this->confirm(trans('command/messages.environment.app.settings'), true) ? 'false' : 'true';
         }