Webclient fix NPE

[SylvainJuge]

What does this PR do?

Relates to #2701

Checklist

• This is a bugfix
  • I have updated CHANGELOG.asciidoc
  • I have added tests that would fail without this fix

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Build stats

• Start Time: 2022-07-08T08:57:57.192+0000

• Duration: 51 min 20 sec

Test stats 🧪

Test	Results
Failed	0
Passed	3054
Skipped	36
Total	3090

💚 Flaky test report

Tests succeeded.

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