Update csrf_in_login_form.rst

We want to protect against CSRF, not allow it. :)
minor #3819 Update csrf_in_login_form.rst (micheal)

This PR was submitted for the 2.4 branch but it was merged into the 2.3 branch instead (closes #3819).

Discussion
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Update csrf_in_login_form.rst

We want to protect against CSRF, not allow it. :)

Commits
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8d80e22 Update csrf_in_login_form.rst