core: Remove unused string

This was mistakenly added on https://github.com/CyanogenMod/android_frameworks_base/commit/9337d51a9ea31ab77392a3988446aadb57d4eba0

Change-Id: I6b2b2c0dabafa3537b8c5152e0393ef5c828e64b

Conflicts:
	core/res/res/values-it/cm_strings.xml
blah

Change-Id: Ic3d9d6c06333124c250523c05daa051848f2e48b