Comment 9 for bug 1480584

Well I understand the reluctance to respond to bugs in another project, but the patch for this issue does not add much.
To be specific it remembers the cross-hair position, does the calculation as happened without the patch before and then checks if an update is really necessary by using one if-conditional.
I am not a developer of kicad, but is 1 variable and 1 conditional (a sanity check) and two lines of commentary too much?