Add missing line ending

Author: DMalone87

backend/database/models/attachment.py

@@ -49,4 +49,4 @@ class SocialMediaInfo(StructuredNode, JsonSerializable):
     facebook_url = StringProperty()
     instagram_url = StringProperty()
     youtube_url = StringProperty()
-    tiktok_url = StringProperty()
+    tiktok_url = StringProperty()