nrf_log fixes in SDK14.1.0

I've noticed following line in SDK14.1 release notes:

`

  • Fixed a bug where nrf_log could crash when heavily loaded. `

I'm using SDK13.1 in my current project and I'm experiencing nrf_log related crashes under load as described here.

Please elaborate on what exactly was fixed and if it's related to problems I'm experiencing. Also if possible please provide some pointers on how to backport this fix into SDK13.1. Unfortunately I can't upgrade to SDK14.1 at this time.