X on Linux (Xfce) it advances by page, by shift-clicking in the gutter! Where do I reverse this? So that it advances by page when clicking in the gutter, and i

X on Linux (Xfce) it advances by page, by shift-clicking in the gutter! Where do I reverse this? So that it advances by page when clicking in the gutter, and it jumps to that position when shift-clicking in the gutter.