BZ 799050 - Initialize @details_tab outside of filter_view
BZ 799050 - Initialize @details_tab outside of filter_view

Otherwise, pools.json tries to reference @details_tab[:id] when
@details_tab is nil, causing an exception. This just moves the setup
higher, so that it's available even if filter_view? is false, so that
it is available for use in the format.json section as well.

Resolves https://bugzilla.redhat.com/show_bug.cgi?id=799050

aeolusproject/conductor,aeolusproject/conductor,aeolusproject/conductor,aeolusproject/conductor