Fixed bug causing error 500 on production

Some PHP version or configuration were causing this error.

On app.blade.php of local branch, I could use "$usedItems ? :"
even if $usedItems were null, but I had to check an "isset" to the production.

On HomecController, I had to change the "object" parameter of getUsername
to "\Illuminate\Database\Eloquent\Collection" to make it work.

I took the chance to just show the number of itens in use
if it were greater than 0.

resources/views/layouts/app.blade.php

@@ -8,7 +8,7 @@
     <!-- CSRF Token -->
     <meta name="csrf-token" content="{{ csrf_token() }}">
 
-    <title>{{ config('app.name', 'Laravel') }} {{ isset($usedItems) ? "(${usedItems})" : '' }}</title>
+    <title>{{ config('app.name', 'Laravel') }} {{ isset($usedItems) && $usedItems > 0 ? "(${usedItems})" : '' }}</title>
 
     <!-- Scripts -->
     <script src="{{ asset('js/app.js') }}" defer></script>