Patch ImageComponent.php(Visual Editor v8.x-2.1)

# This patch file was generated by NetBeans IDE
# It uses platform neutral UTF-8 encoding and \n newlines.
--- <html>ImageComponent.php (<b>23 Sep, 2017 5:46:10 PM</b>)</html>
+++ <html><b>Current File</b></html>
@@ -67,9 +67,9 @@
     }else{
       $files = !empty($content['media']['table']) ? array_keys($content['media']['table']) : [];
       if (!empty($files)) {
-        foreach ($files as $file) {
+        foreach ($files as $key => $file) {
           $build[$key] = parent::getBuild($settings);
-          $build[$key]['#attributes']['alt'] = $content['media']['table'][$key]['alt'];
\ No newline at end of file
+          $build[$key]['#attributes']['alt'] = isset($content['media']['table'][$key]['alt'])?$content['media']['table'][$key]['alt']:'';
\ No newline at end of file
           $build[$key] = $this->renderImage($file, $content['image_format'], $build[$key]);
         }
       }