Fix compilation of top-level POM by splitting out a profile
Fix compilation of top-level POM by splitting out a profile

The parent POM is not supposed to build bundles itself, instead just
providing the configuration of the Maven plugins so that its children
can generate bundles.

So let's just put the executions into a profile that is activated by
default only if src/main/java exists.

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

knime-ip/knip-externals