Issue #22053: Make help work, after previous patch for this issue disabled it

by removing global 'demo'. Simple fix because 2.7/3.4 fix cannot merge.

Lib/turtledemo/__main__.py

@@ -121,7 +121,7 @@ class DemoWindow(object):
         self.mBar = Frame(root, relief=RAISED, borderwidth=2)
         self.ExamplesBtn = self.makeLoadDemoMenu()
         self.OptionsBtn = self.makeHelpMenu()
-        self.mBar.tk_menuBar(self.ExamplesBtn, self.OptionsBtn)
+        #self.mBar.tk_menuBar(self.ExamplesBtn, self.OptionsBtn)
         self.mBar.grid(row=0, columnspan=4, sticky='news')
 
         pane = PanedWindow(orient=HORIZONTAL, sashwidth=5,
@@ -321,6 +321,7 @@ class DemoWindow(object):
 
 
 def main():
+    global demo
     demo = DemoWindow()
     demo.root.mainloop()