minor #17538 Increase the inlining YAML level for config:debug (javiereguiluz)

This PR was submitted for the master branch but it was merged into the 2.7 branch instead (closes #17538).

Discussion
----------

Increase the inlining YAML level for config:debug

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | yes
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #16882
| License       | MIT
| Doc PR        | -

### Before

![debug_before](https://cloud.githubusercontent.com/assets/73419/12575512/52862d3c-c40d-11e5-9bc9-45e24c14b6e2.png)

### After

![debug_after](https://cloud.githubusercontent.com/assets/73419/12575515/5607b868-c40d-11e5-9578-5f004e4ad8df.png)

The new `6` number is completely arbitrary. I chose it because it's the minimum level that makes all the default Symfony services look right. I'm open to better recommendations.

Commits
-------

37655be Increase the inlining YAML level for config:debug

src/Symfony/Bundle/FrameworkBundle/Command/ConfigDebugCommand.php

@@ -90,7 +90,7 @@ EOF
             $output->writeln(sprintf('# Current configuration for "%s"', $name));
         }
 
-        $output->writeln(Yaml::dump(array($extension->getAlias() => $config), 3));
+        $output->writeln(Yaml::dump(array($extension->getAlias() => $config), 10));
     }
 
     private function compileContainer()