[3.6]bpo-29995: Adjust IDLE test for 3.7 re.escape change [GH-1007] (#2114)

Author: terryjreedy

Lib/idlelib/idle_test/test_replace.py

@@ -221,8 +221,8 @@ def test_replace_regex(self):
         self.assertIn('Invalid Replace Expression', showerror.message)
 
         # test access method
-        self.engine.setcookedpat("\'")
-        equal(pv.get(), "\\'")
+        self.engine.setcookedpat("?")
+        equal(pv.get(), "\\?")
 
     def test_replace_backwards(self):
         equal = self.assertEqual