Blockbase: Remove unnecessary normalize code (#4802)

blockbase/assets/ponyfill.css

@@ -2,21 +2,11 @@
  * Base
  * - Reset the browser
  */
-body {
-	margin: 0;
-	padding: 0;
-}
-
 body {
 	-webkit-font-smoothing: antialiased;
 	-moz-osx-font-smoothing: grayscale;
 }
 
-img {
-	height: auto;
-	max-width: 100%;
-}
-
 * {
 	box-sizing: border-box;
 }

blockbase/sass/base/_normalize.scss

@@ -1,26 +1,13 @@
-
-// Remove the margin in all browsers.
-body {
-  margin: 0;
-  padding: 0;
-}
-
 // Smooth out the fonts
 body {
 	-webkit-font-smoothing: antialiased;
 	-moz-osx-font-smoothing: grayscale;
 }
 
-// Needed until https://github.com/WordPress/gutenberg/pull/27518/ is merged.
-img {
-	height: auto;
-	max-width: 100%;
-}
-
 * {
 	box-sizing: border-box;
 }
 
 pre {
-	overflow: scroll;	
-}
+	overflow: scroll;
+}