minor symfony#20741 [DependencyInjection] fix a test checking for a value (xabbuh)

This PR was merged into the 2.7 branch.

Discussion
----------

[DependencyInjection] fix a test checking for a value

| Q             | A
| ------------- | ---
| Branch?       | 2.7
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | 5f62f01
| License       | MIT
| Doc PR        |

Commits
-------

aea0478 fix a test checking for a value

Author: nicolas-grekas

src/Symfony/Component/DependencyInjection/Compiler/CheckCircularReferencesPass.php

@@ -62,7 +62,7 @@ private function checkOutEdges(array $edges)
             if (empty($this->checkedNodes[$id])) {
 
                 // don't check circular dependencies for lazy services
-                if (!$node->getValue() && $node->getValue()->isLazy()) {
+                if (!$node->getValue() || !$node->getValue()->isLazy()) {
                     $searchKey = array_search($id, $this->currentPath);
                     $this->currentPath[] = $id;