Change Type: Bugs Fix (fix icon and .pro for labo )

Bug Description: Since the previous merge, icon disapear and the fitsviewLabo.pro is not relevant

Proposed Fix: reset correctly the icon call in fitsView.cpp (line lost in the merge)
              complete the fitsView labo to allow the use of qcustomplot

How to verify: qmake fitsViewLabo.pro)
               compile
               run (if it compiles and runs, the fitsViewLabo issue is fixed)
               check the icon is present