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

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

Change-Id: Ied8bda3ccf7b718ae53e8c65750aecf3e624d05e
Signed-off-by: Edwin Kempin <edwin.kempin@sap.com>