Add db_index to device_id field

Fixes jazzband#126

Author: jleclanche

push_notifications/models.py

@@ -45,7 +45,7 @@ class GCMDevice(Device):
 	# device_id cannot be a reliable primary key as fragmentation between different devices
 	# can make it turn out to be null and such:
 	# http://android-developers.blogspot.co.uk/2011/03/identifying-app-installations.html
-	device_id = HexIntegerField(verbose_name=_("Device ID"), blank=True, null=True,
+	device_id = HexIntegerField(verbose_name=_("Device ID"), blank=True, null=True, db_index=True,
 		help_text=_("ANDROID_ID / TelephonyManager.getDeviceId() (always as hex)"))
 	registration_id = models.TextField(verbose_name=_("Registration ID"))
 
@@ -77,7 +77,7 @@ def send_message(self, message, **kwargs):
 
 
 class APNSDevice(Device):
-	device_id = UUIDField(verbose_name=_("Device ID"), blank=True, null=True,
+	device_id = UUIDField(verbose_name=_("Device ID"), blank=True, null=True, db_index=True,
 		help_text="UDID / UIDevice.identifierForVendor()")
 	registration_id = models.CharField(verbose_name=_("Registration ID"), max_length=64, unique=True)