Changed background-repeat property to no-repeat

"none" is not at valid value for the background-repeat property. Updated to "no-repeat"

less/agency.less

@@ -163,7 +163,7 @@ h1, h2, h3, h4, h5, h6 {
 
 header {
 	background-image: url('../img/header-bg.jpg');
-	background-repeat: none;
+	background-repeat: no-repeat;
 	background-attachment: scroll;
 	background-position: center center;
 	.background-cover;
@@ -725,4 +725,4 @@ img::-moz-selection {
 
 body {
     webkit-tap-highlight-color: @brand-primary;
-}
+}