When duplicating a Data Template errors can appear in the Cacti log

[TheWitness]

Describe the bug

When you duplicate the Same Data Template more than once, you will receive Error in the Cacti Log. These errors are harmless, but can cause confusion.

To Reproduce

Steps to reproduce the behavior:

1. Duplicate a Data Template

2. Duplicate it a second time

3. See error

Expected behavior

No error messages in Cacti Log.