minor #11900 Fixes typo. Replaces "than" with "as". (dugajean)

This PR was submitted for the 4.3 branch but it was merged into the 4.2 branch instead (closes #11900).

Discussion
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Fixes typo. Replaces "than" with "as".

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Commits
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4884847 Fixes typo. Replaces "than" with "as".

Author: javiereguiluz

mercure.rst

@@ -101,7 +101,7 @@ to the Mercure Hub to be authorized to publish updates.
 
 This JWT should be stored in the ``MERCURE_JWT_SECRET`` environment variable.
 
-The JWT must be signed with the same secret key than the one used by
+The JWT must be signed with the same secret key as the one used by
 the Hub to verify the JWT (``aVerySecretKey`` in our example).
 Its payload must contain at least the following structure to be allowed to
 publish: