[DependencyInjection] Fix parameter description in ConfigurationExtensionInterface

| Q             | A
| ------------- | ---
| Fixed tickets | #10845
| License       | MIT

This fixes the description of parameter `array $config` in file ConfigurationExtensionInterface.php by removing the extra `$config`.
minor #10847 DependencyInjection] Fix parameter description in ConfigurationExtensionInterface (n-aleha)

This PR was merged into the 2.3 branch.

Discussion
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DependencyInjection] Fix parameter description in ConfigurationExtensionInterface

| Q             | A
| ------------- | ---
| Fixed tickets | #10845
| License       | MIT

This fixes the description of parameter `array $config` in file [ConfigurationExtensionInterface.php](https://github.com/symfony/symfony/blob/2.3/src/Symfony/Component/DependencyInjection/Extension/ConfigurationExtensionInterface.php) by removing the extra `$config`.

Commits
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93544aa [DependencyInjection] Fix parameter description in ConfigurationExtensionInterface