use __import__() to dynamically load modules

gallery_dl/downloader/__init__.py

@@ -1,6 +1,6 @@
 # -*- coding: utf-8 -*-
 
-# Copyright 2015-2019 Mike Fährmann
+# Copyright 2015-2021 Mike Fährmann
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License version 2 as
@@ -8,8 +8,6 @@
 
 """Downloader modules"""
 
-import importlib
-
 modules = [
     "http",
     "text",
@@ -24,22 +22,22 @@ def find(scheme):
     except KeyError:
         pass
 
-    klass = None
+    cls = None
     if scheme == "https":
         scheme = "http"
     if scheme in modules:  # prevent unwanted imports
         try:
-            module = importlib.import_module("." + scheme, __package__)
+            module = __import__(scheme, globals(), None, (), 1)
         except ImportError:
             pass
         else:
-            klass = module.__downloader__
+            cls = module.__downloader__
 
     if scheme == "http":
-        _cache["http"] = _cache["https"] = klass
+        _cache["http"] = _cache["https"] = cls
     else:
-        _cache[scheme] = klass
-    return klass
+        _cache[scheme] = cls
+    return cls
 
 
 # --------------------------------------------------------------------