Don't try to use custom_plugins when folder doesn't exist

couchpotato/core/loader.py

@@ -32,6 +32,7 @@ class Loader(object):
         # Add custom plugin folder
         from couchpotato.environment import Env
         custom_plugin_dir = os.path.join(Env.get('data_dir'), 'custom_plugins')
+        if os.path.isdir(custom_plugin_dir):
             sys.path.insert(0, custom_plugin_dir)
             self.paths['custom_plugins'] = (30, '', custom_plugin_dir)