bug #34728 [DI] fix overriding existing services with aliases for singly-implemented interfaces (nicolas-grekas)

This PR was merged into the 4.4 branch.

Discussion
----------

[DI] fix overriding existing services with aliases for singly-implemented interfaces

| Q             | A
| ------------- | ---
| Branch?       | 4.4
| Bug fix?      | yes
| New feature?  | no
| Deprecations? | no
| Tickets       | Fix #34670
| License       | MIT
| Doc PR        | -

Commits
-------

739357656d [DI] fix overriding existing services with aliases for singly-implemented interfaces

Author: nicolas-grekas

Loader/FileLoader.php

@@ -121,7 +121,7 @@ public function registerClasses(Definition $prototype, $namespace, $resource, $e
     public function registerAliasesForSinglyImplementedInterfaces()
     {
         foreach ($this->interfaces as $interface) {
-            if (!empty($this->singlyImplemented[$interface]) && !$this->container->hasAlias($interface)) {
+            if (!empty($this->singlyImplemented[$interface]) && !$this->container->has($interface)) {
                 $this->container->setAlias($interface, $this->singlyImplemented[$interface])->setPublic(false);
             }
         }