Do not "lock" camera when searching with coordinates in the Sector View

[WKFO]

Thanks a lot @fluffyfreak for #4341 . :)
Though I just have a minor complaint.

Observed behaviour

When moving the SectorView camera by entering coordinates to the search field, the camera position gets "locked" to the coordinates and you can't move it. I think it might be caused by the camera position being updated every frame. If you delete the coordinates in the search field the camera "unlocks" and you are free to move again.

But, while deleting (or writing) coordinates, if the z coordinate has more than one digits, the camera parses every string and bounces around trying to go everywhere you write.

For example, if you want to go to (11, -5, -28), the camera first goes to (11, -5, -2) and then bounces to (11, -5, -28). Same while deleting.

Preferable fix

Only try to move the camera ONCE when 'Enter' is pressed. It seemed to work pretty well before.

My pioneer version (and OS):
Latest master, Windows 10 Enterprise