Fix search results when $wgDebugToolbar is enabled

When $wgDebugToolbar is enabled, a debuginfo key is always returned from the
API.
Unfortunately that broke the ve.isArray check on the result, breaking the
opensearch calls by the linker.

Change-Id: I907ef6fc2589581cf7333af3968b63b483af65a9
Merge "Fix search results when $wgDebugToolbar is enabled"