Fix NullPointerException.

If we don't get a location (e.g. because there's no running network
location provider and there was no GPS fix yet), refuse the update
instead of crashing.

Change-Id: Ia09a3557b0a829fa6f2676f17bcc0858a86e8580
Merge branch 'cm-10.1' of github.com:CyanogenMod/android_packages_apps_LockClock into cm-10.1