fix: [ExoDrawer component] When using attribute attached on a second …

…level drawer, the drawer is not attached to the application

Before this fix, when the ExoDrawerComponent is used with attached parameter, with a second level drawer, the drawer is not attached to the application.
This is due to a test which verify if there is more that one opened drawer.
This test comes from olf part of the code and is no more necessary.

Resolved Meeds-io/meeds#2226

webapp/portlet/src/main/webapp/vue-apps/common/components/ExoDrawer.vue

@@ -261,7 +261,7 @@ export default {
   },
   methods: {
     open() {
-      if (!this.attached || eXo.openedDrawers.length) {
+      if (!this.attached) {
         // Re-append the drawer to open in order
         // to ensure to attribute an adequate z-index
         // Which makes it displayed on top of other already
@@ -331,4 +331,4 @@ export default {
     },
   },
 };
-</script>
+</script>