Bump to pom-loci 1.15

This change removes no-longer-needed license-maven-plugin configuration,
since it is inherited from the pom-scijava parent now.

It also updates the CI management URL:
* The Jenkins is really the ImageJ Jenkins; and
* Linking directly to the LOCI view (/view/LOCI/) is clearer.

Lastly, it switches to the combined repository group imagej.public.