Video player in project header bug (firefox):

Unable to play video in in project header in firefox.

Reason:
Firefox is missing ResizeObserver, so as a workaround videoJs inserts an
iframe bellow the video and listens to resize events on that. This iframe
lands in front of the video when we use the class ".embed-responsive",
and therefore we can not start the wideo.

Solution:
I could not see any difference in how the page was rendered
with/without this class so I removed it.

src/templates/projects/view_embed.pug

@@ -4,7 +4,7 @@ include ../mixins/components
 | {% block body %}
 section.node-preview
 	| {% if header_video_file %}
-	.embed-responsive.embed-responsive-16by9
+	.embed-responsive-16by9
 		video#videoplayer.video-js.vjs-fluid.embed-responsive-item(
 			controls,
 			data-setup="{}",