README.md: Update kernel to 4.9.43

Author: rajivr

README.md

@@ -23,7 +23,7 @@ system that powers [AWS](https://aws.amazon.com/).
 <a name="container_host"></a>
 ### Container Host
 
-* LTS Kernel [v4.9.32](https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.9.32)
+* LTS Kernel [v4.9.43](https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.9.43)
 * VirtualBox Guest Additions [v5.1.20](http://download.virtualbox.org/virtualbox/5.1.20/)
 * Docker [v17.03.1-ce](https://github.com/moby/moby/releases/tag/v17.03.1-ce)
 * Device mapper storage driver in [direct-lvm](https://docs.docker.com/engine/userguide/storagedriver/device-mapper-driver) mode