fix unit test

Author: patrykgruszka

app/bundles/CoreBundle/Tests/Unit/Helper/FileUploaderTest.php

@@ -113,6 +113,9 @@ public function testCouldNotMoveFile(): void
             ->disableOriginalConstructor()
             ->getMock();
 
+        $translatorMock->method('trans')
+            ->willReturn('Could not upload filed');
+
         $fileMock = $this->getMockBuilder(UploadedFile::class)
             ->disableOriginalConstructor()
             ->getMock();