Revert "Make an empty "?action=" parameter default to "view""

Breaks all non-view actions on dev wikis, something's not right with the patch.

This reverts commit a90b7ea969b4332a6229be1c4160190a3ec79200.

Change-Id: Ib9a5eb07ef48716df193fbb62a86c13e5c80dafd
Merge "Revert "Make an empty "?action=" parameter default to "view"""