BatchModeTest: don't use the graphics environment for testing.
BatchModeTest: don't use the graphics environment for testing.

The test now could also work without a graphics environment. But the truth
is, that it's the legacy UI batch mode work with SciJava commends. The test
fails if the legacy UI is not visible. This should ideally be fixed in the
future.

imagej/imagej-legacy,imagej/imagej-legacy,imagej/imagej-legacy,imagej/imagej-legacy