Update normalize to 4.2.0.

src/_h5ai/public/css/vendor/normalize.less

@@ -1,14 +1,16 @@
-/* normalize.css v4.1.1 | MIT License | github.com/necolas/normalize.css */
+/* normalize.css v4.2.0 | MIT License | github.com/necolas/normalize.css */
 
 /**
  * 1. Change the default font family in all browsers (opinionated).
- * 2. Prevent adjustments of font size after orientation changes in IE and iOS.
+ * 2. Correct the line height in all browsers.
+ * 3. Prevent adjustments of font size after orientation changes in IE and iOS.
  */
 
 html {
   font-family: sans-serif; /* 1 */
-  -ms-text-size-adjust: 100%; /* 2 */
-  -webkit-text-size-adjust: 100%; /* 2 */
+  line-height: 1.15; /* 2 */
+  -ms-text-size-adjust: 100%; /* 3 */
+  -webkit-text-size-adjust: 100%; /* 3 */
 }
 
 /**
@@ -154,20 +156,6 @@ h1 {
   margin: 0.67em 0;
 }
 
-/**
- * Correct the line-height for all headings in Chrome mobile, Firefox,
- * iOS Safari, Microsoft Edge and IE.
- */
-
-h1,
-h2,
-h3,
-h4,
-h5,
-h6 {
-  line-height: 1.15;
-}
-
 /**
  * Add the correct background and color in IE 9-.
  */