Stretch the buttons correctly

qt/widgets/instrumentview/src/InstrumentWidgetMaskTab.cpp

@@ -170,7 +170,7 @@ InstrumentWidgetMaskTab::InstrumentWidgetMaskTab(InstrumentWidget *instrWidget)
   toolBox->addWidget(m_free_draw, 0, 7);
   toolBox->addWidget(m_pixel, 1, 0);
   toolBox->addWidget(m_tube, 1, 1);
-  toolBox->setColumnStretch(1, 1);
+  toolBox->setColumnStretch(8, 1);
   toolBox->setSpacing(2);
 
   connect(m_move, SIGNAL(clicked()), this, SLOT(setActivity()));

qt/widgets/instrumentview/src/InstrumentWidgetPickTab.cpp

@@ -274,7 +274,7 @@ InstrumentWidgetPickTab::InstrumentWidgetPickTab(InstrumentWidget *instrWidget)
   toolBox->addWidget(m_peakSelect, 1, 3);
   toolBox->addWidget(m_peakCompare, 1, 4);
   toolBox->addWidget(m_peakAlign, 1, 5);
-  toolBox->setColumnStretch(6, 1);
+  toolBox->setColumnStretch(8, 1);
   toolBox->setSpacing(2);
   connect(m_zoom, SIGNAL(clicked()), this, SLOT(setSelectionType()));
   connect(m_one, SIGNAL(clicked()), this, SLOT(setSelectionType()));