test_locale now ignores the DeprecationWarning (#977)

Don't fail anymore if test run with python3 -Werror.

Fix also deprecation message: add a space.
diff --git a/Lib/locale.py b/Lib/locale.py
index 50cd652..73fc94d 100644
--- a/Lib/locale.py
+++ b/Lib/locale.py
@@ -245,7 +245,7 @@
 def format(percent, value, grouping=False, monetary=False, *additional):
     """Deprecated, use format_string instead."""
     warnings.warn(
-        "This method will be removed in a future version of Python."
+        "This method will be removed in a future version of Python. "
         "Use 'locale.format_string()' instead.",
         DeprecationWarning, stacklevel=2
     )