Fix a typo at the common-problems documentation file

[florianrusch]

What's this PR do/fix?

There is a typo at the common-problems.adoc file.

Are there unit tests? If not how should this be manually tested?

Just take a view. It's not a big thing.

Any background context you want to provide?

Nope :)

What are the relevant issues?

There is no issue for this PR.

[codecov]

Codecov Report

Merging #1730 into master will not change coverage.
The diff coverage is n/a.

@@ Coverage Diff @@ ## master #1730 +/- ## ========================================= Coverage 91.41% 91.41% Complexity 2490 2490 ========================================= Files 298 298 Lines 5695 5695 Branches 470 470 ========================================= Hits 5206 5206 Misses 408 408 Partials 81 81

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[dilipkrish]

Thanks!