fix: adjusted sharing icon with the new one.

LBSD-597

Author: nistormihai

gui-themes/themes/zeit-online-solo/img/sharing_b.png

@@ -222,7 +222,7 @@ $publisher-avatar-width: em(42px);
 			font-size: em(14px);
 			line-height: 2;
 			color: inherit;
-			background: transparent url("img/share.png") no-repeat 0 0;
+			background: transparent url("img/sharing_b.png") no-repeat scroll 12px 12px / 20px auto;
 			padding: 5px 0 5px 48px;
 			float: right;
 			overflow: hidden;