Fixed aggregation for dActionWhen conditions

[podcherklife]

So grammar allows specifying a list of conditions for some d actions, but as of now values are not properly folded, the last condition always wins.

This is obviously an oversight, but this fix is kind of questionable. Like, should should conditions be combined with || or with &&? && seems more intuitive, but || seems more useful. Does it even make sense at all, why would anybody want to have two separate conditions instead of combining them into a single regex? I've searched through a quite extensive(but not exhaustive) list of .d files and none was using more than 1 condition.
Questions, questions...

Nevertheless, something should be dome about this, even if just adding a warning about dead conditions.

[FredrikLindgren]

TP2-when folds with && and I think it would be less astonishing if D-when worked the same. However, there is the issue of backward-compatibility which you note. I'll think about it.