Replace backticks with repr() or "%r"

From SF patch #852334.
diff --git a/Lib/test/test_minidom.py b/Lib/test/test_minidom.py
index cb84987..a54fbd3 100644
--- a/Lib/test/test_minidom.py
+++ b/Lib/test/test_minidom.py
@@ -1361,7 +1361,7 @@
             print "Test Failed: ", name
             sys.stdout.flush()
             traceback.print_exception(*sys.exc_info())
-            print `sys.exc_info()[1]`
+            print repr(sys.exc_info()[1])
             Node.allnodes = {}
 
 if failed: