Morden: Add box-shadow back to the dropdown

morden/sass/_extra-child-theme.scss

@@ -191,7 +191,6 @@ body {
 					background: #{map-deep-get($config-global, "color", "primary", "default")};
 					border: 1px solid darken(map-deep-get($config-global, "color", "primary", "default"), 20%);
 					border-radius: #{map-deep-get($config-global, "border-radius", "sm")};
-					box-shadow: none;
 					overflow: hidden;
 				}
 

morden/style-rtl.css

@@ -3482,7 +3482,6 @@ body {
 		background: #E22C2C;
 		border: 1px solid #941414;
 		border-radius: 5px;
-		box-shadow: none;
 		overflow: hidden;
 	}
 	.site-header .main-navigation > div > ul > li:hover li,

morden/style.css

@@ -3487,7 +3487,6 @@ body {
 		background: #E22C2C;
 		border: 1px solid #941414;
 		border-radius: 5px;
-		box-shadow: none;
 		overflow: hidden;
 	}
 	.site-header .main-navigation > div > ul > li:hover li,