bootstrap.js: restructure for readability
bootstrap.js: restructure for readability

Now we require one less level of indentation. As a consequence, this
commit is easier to read with Git's -w option (ignoring whitespace
changes).

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

imagejan/imagej-updater