Revert change 291d47954618

Revert:
"Always test datetime.strftime("%4Y")

Issue #13305: Always test datetime.datetime.strftime("%4Y") for years < 1900."

In fact, strftime("%4Y") fails on most platforms.
diff --git a/Lib/test/datetimetester.py b/Lib/test/datetimetester.py
index 0be1af4..b49942a 100644
--- a/Lib/test/datetimetester.py
+++ b/Lib/test/datetimetester.py
@@ -1422,8 +1422,8 @@
             if d.strftime("%Y") != '%04d' % y:
                 # Year 42 returns '42', not padded
                 self.assertEqual(d.strftime("%Y"), '%d' % y)
-            # '0042' is obtained anyway
-            self.assertEqual(d.strftime("%4Y"), '%04d' % y)
+                # '0042' is obtained anyway
+                self.assertEqual(d.strftime("%4Y"), '%04d' % y)
 
     def test_replace(self):
         cls = self.theclass