Do not violate G-7510 in good example of G-5080

The good example in [G-5080](https://trivadis.github.io/plsql-and-sql-coding-guidelines/v4.2/4-language-usage/5-exception-handling/g-5080/#example-good) violates G-7510. 

change 

```sql
|| dbms_utility.format_error_backtrace
```

to 

```sql
|| sys.dbms_utility.format_error_backtrace
```
