09ea3a424f moved the console above the OSC when it is visible so they
don't overlap, but only changed the first ass:pos() call and forgot to
update the second one, which redraws the cursor on top of the text, so
when both the OSC and the console are visible, a second cursor is drawn
on the OSC. You have to type past where the buttons are to notice it.
This commit synchronizes the position of the 2 ASS events.