Fixed updating guild icon

src/Discord/Parts/Guild/Guild.php

@@ -427,7 +427,7 @@ public function getCreatableAttributes(): array
         return [
             'name' => $this->name,
             'region' => $this->region,
-            'icon' => $this->icon,
+            'icon' => $this->attributes['icon'],
             'verification_level' => $this->verification_level,
             'default_message_notifications' => $this->default_message_notifications,
             'explicit_content_filter' => $this->explicit_content_filter,
@@ -450,9 +450,9 @@ public function getUpdatableAttributes(): array
             'explicit_content_filter' => $this->explicit_content_filter,
             'afk_channel_id' => $this->afk_channel_id,
             'afk_timeout' => $this->afk_timeout,
-            'icon' => $this->icon,
-            'splash' => $this->splash,
-            'banner' => $this->banner,
+            'icon' => $this->attributes['icon'],
+            'splash' => $this->attributes['splash'],
+            'banner' => $this->attributes['banner'],
             'system_channel_id' => $this->system_channel_id,
             'rules_channel_id' => $this->rules_channel_id,
             'public_updates_channel_id' => $this->public_updates_channel_id,

src/Discord/functions.php

@@ -180,7 +180,7 @@ function imageToBase64(string $filepath): string
         throw new \InvalidArgumentException('The given filepath does not exist.');
     }
 
-    $mimetype = mime_content_type($filepath);
+    $mimetype = \mime_content_type($filepath);
 
     if (array_search($mimetype, ['image/jpeg', 'image/png', 'image/gif']) === false) {
         throw new \InvalidArgumentException('The given filepath is not one of jpeg, png or gif.');