Fix typo

app/jobs/forms.py

@@ -71,7 +71,7 @@ class AddOCRJobForm(FlaskForm):
 class AddMergeImagesJobForm(FlaskForm):
     files = MultipleFileField('Files', validators=[DataRequired()])
 
-    def validate_files(form, filed):
+    def validate_files(form, field):
         for file in field.data:
             if not file.filename.lower().endswith(('.jpeg', '.jpg', '.png',
                                                    '.tiff', '.tif')):