Google has started rolling out a bug-fixing KitKat OTA update for all the previous generation of Nexus devices, including the Nexus 4. The 3-5MB OTA update bumps the Android build to KRT16S vs. the initial KitKat KRT16O update that it released last week.
The company has also updated the binaries, AOSP code and even pushed the kernel sources for the Nexus 4, Nexus 7 (2012/2013) and the Nexus 10, which were missing until now. The download link of factory images have also been updated with the newer build of KitKat.
The OTA update does not bring any visible changes, except for prompting users to specify a backup account, if they have multiple Google accounts on their devices on first boot after the installation.