Allow higher level GMs to bypass a player's /exall when whispering

- Follow-up to 3d0fba0
- Fixes the remaining part of bug #7463:
http://hercules.ws/board/tracker/issue-7463-gm-cant-whsiper-wheb-player-do-exall

Signed-off-by: Haru <haru@dotalux.com>