Add init step to copy configuration from the 'hooks-bugzilla' plugin

The 'its-bugzilla' plugin replaces the 'hooks-bugzilla' plugin. The
configuration for both plugins only differs in the section names. If
the 'hooks-bugzilla' plugin was previously installed its configuration
can simply be copied for the 'its-bugzilla' plugin.

Change-Id: I080a23c5d591ab3e9d7e35c609bb3fa2d15faa5e
Signed-off-by: Edwin Kempin <edwin.kempin@sap.com>