Fix typo in the check_path validator
merged branch unkind/security-bundle-check-path-bugfix (PR #8782)

This PR was submitted for the master branch but it was merged into the 2.2 branch instead (closes #8782).

Discussion
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[SecurityBundle] Fix typo in the check_path validator

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #3005, #2954
| License       | MIT

Actually, validator of `check_path` value is broken by #3005. It doesn't throw any exception even if `check_path` is an URI.

I've faced with wrong tests class hierarchy: `SecurityExtensionTest` is abstract test and I have to create the same test configuration for every format: PHP, XML, YAML. It looks like we test `Dependency Injection` and `Yaml` components. Issue with `check_path` does not depend on format, but such class hierarchy leaves me no choice. And I can't put test case into `ConfigurationTest`, because it doesn't know anything about security factories.

It looks like it's better to create new class for `SecurityExtension` tests.

Commits
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155dca0 [SecurityBundle] Fix typo in the check_path validator