[ticket/11519] Rename test event template file

As requested by Oleg
https://github.com/phpbb/phpbb3/pull/1340#issuecomment-17306967

PHPBB3-11519
Merge PR #1389 branch 'EXreaction/ticket/11519' into develop

# By Nathaniel Guse
# Via Nathaniel Guse
* EXreaction/ticket/11519:
  [ticket/11519] Rename test event template file