Extract var to allowed to be overridden

services/web/public/stylesheets/app/project-list.less

@@ -1,5 +1,4 @@
 @announcements-shadow: 0 2px 20px rgba(0, 0, 0, 0.5);
-@v1-dash-link-height: 110px;
 
 @keyframes pulse {
 	0% {

services/web/public/stylesheets/core/_common-variables.less

@@ -852,6 +852,7 @@
 @sidebar-active-bg             : @link-color;
 @sidebar-hover-bg              : transparent;
 @sidebar-hover-text-decoration : underline;
+@v1-dash-link-height           : 0;
 
 @folders-menu-margin           : 0;
 @folders-menu-line-height      : 1.2;

services/web/public/stylesheets/core/ol-variables.less

@@ -110,6 +110,7 @@
 @sidebar-active-bg              : @ol-blue-gray-6;
 @sidebar-hover-bg               : @ol-blue-gray-4;
 @sidebar-hover-text-decoration  : none;
+@v1-dash-link-height            : 110px;
 
 @folders-menu-margin            : 0 -(@grid-gutter-width / 2);
 @folders-menu-line-height       : @structured-list-line-height;