Center the indeterminate spinner on HTML5 page

(cherry picked from commit 84982f5778ed2f7136f2b625c851a01823afea44)

misc/dist/html/full-size.html

@@ -80,6 +80,7 @@
 		}
 
 		#status-indeterminate {
+			height: 42px;
 			visibility: visible;
 			position: relative;
 		}