Disable Hello World post in BP

[boonebgorges]

I'd like to suggest that the initial Hello World post (and reply) is disabled for the moment, for a couple of reasons:

• It's a departure from BP's current behavior
• In the context of a group - especially when, as at the present, it's only possible to have one forum per group - guidance is not really needed on what constitutes a group forum (since it was the group forum admin who enabled forums to begin with).

Patch attached.

[johnjamesjacoby]

(In [3799]) BuddyPress group forums:

• Fix new reply and topic redirects
• Remove first group forum topic and reply in lieu of more customization
• See #1669
• Fixes #1776
• Fixes #1778
• Fixes #1777
• Props boonebgorges