Fix typos, remove trailing whitespace.
minor #3657 Fix typos, remove trailing whitespace. (ifdattic)

This PR was merged into the 2.3 branch.

Discussion
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Fix typos, remove trailing whitespace.

| Q             | A
| ------------- | ---
| Doc fix?      | yes
| New docs?     | no
| Applies to    | 2.3
| Fixed tickets |

Commits
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2ec09a3 Fix typos, remove trailing whitespace.