ACP2E-2847: Favicon upload fails to validate .ico files

Author: Chhandak.Barua

dev/tests/integration/testsuite/Magento/Theme/Controller/Adminhtml/System/Design/ThemeControllerTest.php

@@ -63,7 +63,7 @@ public function testUploadFaviconAction()
             $output = $this->getResponse()->getBody();
             if (!in_array('imagick', get_loaded_extensions()) || $this->imageAdapter == 'GD2') {
                 $this->assertStringContainsString(
-                    '{"error":"File validation failed
+                    '{"error":"File validation failed.
                     Check Image Processing Settings in the Store Configuration."',
                     $output
                 );