Fix small bug in navigator tool
Fix small bug in navigator tool

Instead of referencing the y input box the x input box was referenced twice.

fzadow/CATMAID,htem/CATMAID,htem/CATMAID,fzadow/CATMAID,htem/CATMAID,fzadow/CATMAID,htem/CATMAID,fzadow/CATMAID