[FIX] web: kanban mobile horizontal scroll issue

In mobile, the .o_kanban_card_content width wasn't defined.
In desktop, we don't have this issue because the .container bootstrap
element set the width.

Now, the kanban card content is correctly displayed in
the workcenter kanban view.

addons/web/static/src/less/kanban_dashboard.less

@@ -45,7 +45,7 @@
 
         // ------- Generic layout adaptations -------
         .container {
-            max-width: 100%;
+            width: 100%;
         }
 
         // ------- Dropdown toggle & menu -------