Update the usergroups pages.

o Remove SeaBUG, it's been down for at least 5 months
o Re-add VicFUG, it's come back
o Revert the change I submitted (rev. 1.63) to change the GTABUG

URL from gtabug.ca to gtabug.com - gtabug.ca is back, and is more
up-to-date than the .com.

PR: www/124239
Submitted by: gavin