minor #18979 [Security] Update security.rst (profuel)

This PR was submitted for the 6.3 branch but it was merged into the 5.4 branch instead.

Discussion
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[Security] Update security.rst

Fixed the mistype.

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Commits
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eb607a3 Update security.rst

Author: javiereguiluz

security.rst

@@ -2686,7 +2686,7 @@ Frequently Asked Questions
     Sometimes authentication may be successful, but after redirecting, you're
     logged out immediately due to a problem loading the ``User`` from the session.
     To see if this is an issue, check your log file (``var/log/dev.log``) for
-    the log message:
+    the log message.
 
 **Cannot refresh token because user has changed**
     If you see this, there are two possible causes. First, there may be a problem