Custom Data Groups created while logging is disabled break changelogs when logging re-enabled

Steps to Reproduce:

1. Enable Logging
2. Disable Logging
3. Create a Custom Data Group for Contacts with at least one field.
4. Re-Enable Logging
5. Edit a contact, change your custom field.
6. Check contact's changelog, look at "Update" action for new changelog entry.

Expected Results:

Changed field information is displayed.

Actual Results:

Sorry but we are not able to provide this at the moment.
One of parameters (value: ) is not of the type Integer

Backtrace shows that this is due to CRM_Logging_Differ->titlesAndValuesForCustomDataTable assuming that an attempt to find the custom data group in log_civicrm_custom_group will succeed.
This is not true if the Group was created after log_civicrm_custom_group, but while logging was disabled.

The following code appears to make the same assumption about log_civicrm_custom_field.