Fix less file errors

packages/rocketchat-theme/assets/stylesheets/base.less

@@ -2490,8 +2490,6 @@ a.github-fork {
 	}
 	&.new-day {
 		margin-top: 60px;
-	}
-	&.new-day {
 		&:before {
 			content: attr(data-date);
 			display: block;
@@ -2960,11 +2958,6 @@ body:not(.is-cordova) {
 		width: 100%;
 		.message {
 			padding: 8px 0px 4px 50px;
-			&.new-day
-				&:before {
-
-				}
-			}
 		}
 	}
 	> .title {