Correct docblock for bp_has_groups()

[dcavins]

The docblock for bp_has_groups() was missing a couple of parameter names.

Also removed "optional" from each line, since the first line reads "Array of parameters. All items are optional."

[dcavins]

Add missing parameter names.

[DJPaul]

Yay, thanks for the patches. :)

[r-a-y]

In 9221:

Update parameters in DocBlock for bp_has_groups().

Props dcavins. Fixes #6034.