direct: Remove a remaining sys.version_info check

direct/src/extensions_native/CInterval_extensions.py

@@ -63,12 +63,9 @@ def popupControls(self, tl = None):
         import math
         # Don't use a regular import, to prevent ModuleFinder from picking
         # it up as a dependency when building a .p3d package.
-        import importlib, sys
+        import importlib
         EntryScale = importlib.import_module('direct.tkwidgets.EntryScale')
-        if sys.version_info >= (3, 0):
-            tkinter = importlib.import_module('tkinter')
-        else:
-            tkinter = importlib.import_module('Tkinter')
+        tkinter = importlib.import_module('tkinter')
 
         if tl == None:
             tl = tkinter.Toplevel()