group_chars: default change warning only when needed

changelogs/fragments/group-chars-ignore.yaml

@@ -0,0 +1,4 @@
+---
+bugfixes:
+- suppress "default will change" warnings for ``TRANSFORM_INVALID_GROUP_CHARS``
+  setting when non-default option value is chosen

lib/ansible/inventory/group.py

@@ -48,6 +48,8 @@ def to_safe_group_name(name, replacer="_", force=False, silent=False):
                     warn = 'Invalid characters were found in group names but not replaced, use -vvvv to see details'
 
                 # remove this message after 2.10 AND changing the default to 'always'
+                group_chars_setting, group_chars_origin = C.config.get_config_value_and_origin('TRANSFORM_INVALID_GROUP_CHARS')
+                if group_chars_origin == 'default':
                     display.deprecated('The TRANSFORM_INVALID_GROUP_CHARS settings is set to allow bad characters in group names by default,'
                                        ' this will change, but still be user configurable on deprecation', version='2.10')