Restore Shibboleth auth on 2.10.x
Shibboleth auth improvements 2.10.x
Merge pull request #593 from geosolutions-it/210x_shibboleth

Restore Shibboleth auth on 2.10.x
Shibboleth: fix: added a lost variable declaration.
Merge remote-tracking branch 'upstream/2.10.x' into 2.10.x
Merge remote-tracking branch 'upstream/2.10.x' into 2.10.x