Twenty Seventeen: Keep header videos from extending past footer.

This adds 1px of bottom padding to header videos to keep them from
extending past the footer at the bottom of the page.

Fixes #38950.
Built from https://develop.svn.wordpress.org/trunk@39380


git-svn-id: http://core.svn.wordpress.org/trunk@39320 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-content/themes/twentyseventeen/style.css

@@ -1674,6 +1674,7 @@ body:not(.title-tagline-hidden) .site-branding-text {
 	min-width: 100vw; /* vw prevents 1px gap on left that 100% has */
 	width: auto;
 	top: 50%;
+	padding-bottom: 1px; /* Prevent header from extending beyond the footer */
 	-ms-transform: translateX(-50%) translateY(-50%);
 	-moz-transform: translateX(-50%) translateY(-50%);
 	-webkit-transform: translateX(-50%) translateY(-50%);