Remove some useless imports

service/__init__.py

@@ -4,4 +4,4 @@ from service.attribute import Attribute
 from service.character import Character
 from service.damagePattern import DamagePattern
 from service.settings import Settings
-import service.prefetch
+from service import prefetch

service/market.py

@@ -20,7 +20,6 @@
 import eos.db
 import eos.types
 import wx
-import collections
 import threading
 from sqlalchemy.orm.exc import NoResultFound
 import Queue