Bug found by DeepScan

[alexeyr]

https://deepscan.io/dashboard/#view=project&tid=2875&pid=4298&bid=34996&subview=issues

scripts/nextplease_content.js:770:
Assigning to the 'style' property of a string value has no effect. The string value is originated from the for-in variable 'element' defined at line 769 .