minor #12917 [2.3] [Security] Fixed The AuthenticationProviderInterface Alignment (GrahamCampbell)

This PR was merged into the 2.3 branch.

Discussion
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[2.3] [Security] Fixed The AuthenticationProviderInterface Alignment

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | N/A
| License       | MIT
| Doc PR        | N/A

##### This pull request fixes the AuthenticationProviderInterface alignment.

Everything was indented by one too many spaces.

Commits
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1270327 Fixed the AuthenticationProviderInterface alignment

src/Symfony/Component/Security/Core/Authentication/Provider/AuthenticationProviderInterface.php

@@ -24,12 +24,12 @@ use Symfony\Component\Security\Core\Authentication\AuthenticationManagerInterfac
  */
 interface AuthenticationProviderInterface extends AuthenticationManagerInterface
 {
-     /**
-      * Checks whether this provider supports the given token.
-      *
-      * @param TokenInterface $token A TokenInterface instance
-      *
-      * @return bool true if the implementation supports the Token, false otherwise
-      */
-     public function supports(TokenInterface $token);
+    /**
+     * Checks whether this provider supports the given token.
+     *
+     * @param TokenInterface $token A TokenInterface instance
+     *
+     * @return bool true if the implementation supports the Token, false otherwise
+     */
+    public function supports(TokenInterface $token);
 }