Updating to latest LibLog

There was a bug in LibLog 1.4.0 (fixed in [this commit](https://github.com/damianh/LibLog/commit/310e388eb87782fc9713a4c444440b321945d462)) that caused Serilog to check for DebugLevel to be enabled to do any logging.

Updating to the latest NuGet package installs the new source and it works just fine now.

_Workaround until PR is merged - turn on `DebugLevel` in Serilog`_