overview: fix fix auto tab width in FF

app/assets/javascripts/app/controllers/ticket_overview.coffee

@@ -78,6 +78,7 @@ class App.TicketOverview extends App.Controller
 
 class Navbar extends App.Controller
   elements:
+    '.js-tabsHolder': 'tabsHolder'
     '.js-tabsClone': 'clone'
     '.js-tabClone': 'tabClone'
     '.js-tabs': 'tabs'
@@ -129,9 +130,7 @@ class Navbar extends App.Controller
       items: items
       isAgent: @isRole('Agent')
 
-    console.log @el.width(), @clone.width()
-
-    while @clone.width() > @el.width()
+    while @clone.width() > @tabsHolder.width()
       @tabClone.not('.hide').last().addClass('hide')
       @tab.not('.hide').last().addClass('hide')
       @dropdownItem.filter('.hide').last().removeClass('hide')

app/assets/javascripts/app/views/agent_ticket_view/navbar_vertical.jst.eco

@@ -1,4 +1,4 @@
-<div class="tabsHolder">
+<div class="tabsHolder js-tabsHolder">
   <div class="tabs tabs--inline tabs--big js-tabs">
     <% if @items: %>
       <% for item in @items: %>

app/assets/stylesheets/zammad.scss

@@ -2461,6 +2461,7 @@ footer {
   .tabsHolder {
     flex: 1;
     margin-right: 20px;
+    min-width: 0; /* Firefox bug fix */
   }
   
   .tabs {