Don't store search increments in the browser history

Signed-off-by: Chris Abraham <cjyabraham@gmail.com>

website/layouts/_default/search.html

@@ -55,7 +55,7 @@ <h1 class="thin">{{ .Title }}</h1>
 
 		var newUrl = baseUrl + "?" + urlParams.toString();
 		// Update the browser history (optional)
-		window.history.pushState({}, null, newUrl);
+		history.replaceState(null, '', newUrl);
 	}
 	</script>