better slugify support for api

inc/api.php

@@ -34,7 +34,6 @@ class Api {
 			'locked' => 'locked',
 			'bump' => 'last_modified',
 			'embed' => 'embed',
-			'slug' => 'semantic_url',
 		);
 
 		$this->threadsPageFields = array(
@@ -117,6 +116,10 @@ class Api {
 			}
 		}
 
+		if ($config['slugify'] && !$post->thread) {
+			$apiPost['semantic_url'] = $post->slug;
+		}
+
 		// Handle files
 		// Note: 4chan only supports one file, so only the first file is taken into account for 4chan-compatible API.
 		if (isset($post->files) && $post->files && !$threadsPage) {