Utils: Make TreeViews use setUniformRowHeights by default

When applicable, the flag makes a significant difference in
performacnce. However is easily forgotten in cases where it
is applicable, and cases where it is accidentally used are
easily spotted visually. So arguably, opt-out is a better
default than opt-in.

Change-Id: I88aeb05b42533ba4e23c39573a3ddd016343cd55
Reviewed-by: hjk <hjk@qt.io>
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/plugins/git/logchangedialog.cpp

@@ -71,7 +71,6 @@ LogChangeWidget::LogChangeWidget(QWidget *parent)
     m_model->setHorizontalHeaderLabels(headers);
     setModel(m_model);
     setMinimumWidth(300);
-    setUniformRowHeights(true);
     setRootIsDecorated(false);
     setSelectionBehavior(QAbstractItemView::SelectRows);
     setActivationMode(Utils::DoubleClickActivation);