Merge branch '5.1' into 5.2

* 5.1:
  Remove void return type from test methods
  Added basque translations
  Updated Luxembourgish translations
  [Mailer] Fix parsing Dsn with empty user/password
  Normalize exceptions messages containing methods references
  [Ldap] Incorrect determination of RelativeDistinguishedName for the "move" operation

Author: fabpot

Tests/DependencyInjection/Compiler/AddSecurityVotersPassTest.php

@@ -71,7 +71,7 @@ public function testThatSecurityVotersAreProcessedInPriorityOrder()
         $this->assertCount(4, $refs);
     }
 
-    public function testThatVotersAreTraceableInDebugMode(): void
+    public function testThatVotersAreTraceableInDebugMode()
     {
         $container = new ContainerBuilder();
 
@@ -103,7 +103,7 @@ public function testThatVotersAreTraceableInDebugMode(): void
         $this->assertCount(2, $voters, 'Incorrect count of voters');
     }
 
-    public function testThatVotersAreNotTraceableWithoutDebugMode(): void
+    public function testThatVotersAreNotTraceableWithoutDebugMode()
     {
         $container = new ContainerBuilder();
         $container->setParameter('kernel.debug', false);