ImageJ launcher: unbreak compilation on non-Linux
ImageJ launcher: unbreak compilation on non-Linux

My previous fix for Linux broke both MacOSX and Windows builds...

Signed-off-by: Johannes Schindelin <53fb8db7833fca1e1746dd8592f61048d350f64c@gmx.de>

imagej/imagej-launcher,imagej/imagej-launcher,imagej/imagej-launcher