Update Profile model, improve #381

app/Profile.php

@@ -125,14 +125,16 @@ class Profile extends Model
 
     public function avatar()
     {
-        return $this->hasOne(Avatar::class);
+        return $this->hasOne(Avatar::class)->withDefault([
+            'media_path' => 'public/avatars/default.png'
+        ]);
     }
 
     public function avatarUrl()
     {
         $url = Cache::remember("avatar:{$this->id}", 1440, function() {
-            $path = $this->avatar->media_path ?? 'public/avatars/default.png';
-            $version = $this->avatar ? hash('sha1', $this->avatar->created_at) : '';
+            $path = optional($this->avatar)->media_path;
+            $version = hash('sha1', $this->avatar->created_at);
             $path = "{$path}?v={$version}";
             return url(Storage::url($path));
         });