LegacyUI: ignore saveLocation()/restoreLocation() calls

ImageJ 1.x already does its own thing; let's not interfere with it.

This fixes https://github.com/imagej/imagej-legacy/issues/17.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Fix test expecting Dataset service *not* to auto-detect isRGBmerged

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>