minor #11350 Update NotCompromisedPassword.rst (vermeirentony)

This PR was merged into the master branch.

Discussion
----------

Update NotCompromisedPassword.rst

Added missing word

<!--

If your pull request fixes a BUG, use the oldest maintained branch that contains
the bug (see https://symfony.com/roadmap for the list of maintained branches).

If your pull request documents a NEW FEATURE, use the same Symfony branch where
the feature was introduced (and `master` for features of unreleased versions).

-->

Commits
-------

eb45f74 Update NotCompromisedPassword.rst

Author: wouterj

reference/constraints/NotCompromisedPassword.rst

@@ -5,7 +5,7 @@ NotCompromisedPassword
 
     The ``NotCompromisedPassword`` constraint was introduced in Symfony 4.3.
 
-Validates that the given password has not been compromised by checking that is
+Validates that the given password has not been compromised by checking that it is
 not included in any of the public data breaches tracked by `haveibeenpwned.com`_.
 
 ==========  ===================================================================