fix: Do not log unloggable context

[michelbl]

See https://app.asana.com/0/370953015396593/736287362900672

[codecov]

Codecov Report

Merging #207 into master will not change coverage.
The diff coverage is 100%.

@@          Coverage Diff          @@
##           master   #207   +/-   ##
=====================================
  Coverage      89%    89%           
=====================================
  Files          78     78           
  Lines        1573   1573           
  Branches      201    201           
=====================================
  Hits         1400   1400           
  Misses        147    147           
  Partials       26     26

Impacted Files	Coverage Δ
packages/botfuel-dialog/src/nlus/botfuel-nlu.js	86.44% <100%> (ø)	⬆️

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