Fix typo in docs about Elasticsearch

What does this MR do?

Fixes typo in docs about Elasticsearch.

Previous fix was in !15699 (merged) at %10.3.

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation created/updated or follow-up review issue created
• Code review guidelines
• [n/a] Merge request performance guidelines
• [n/a] Style guides
• [n/a] Database guides
• Separation of EE specific content