certmonger: Use explicit storage format

Add storage='NSSDB' to various places. It makes it a bit easier to track
down NSSDB usage.

Signed-off-by: Christian Heimes <cheimes@redhat.com>
Reviewed-By: Stanislav Laznicka <slaznick@redhat.com>

ipaserver/install/dsinstance.py

@@ -832,6 +832,7 @@ class DsInstance(service.Service):
                 cmd = 'restart_dirsrv %s' % self.serverid
                 certmonger.request_and_wait_for_cert(
                     certpath=dirname,
+                    storage='NSSDB',
                     nickname=self.nickname,
                     principal=self.principal,
                     passwd_fname=dsdb.passwd_fname,
@@ -839,7 +840,8 @@ class DsInstance(service.Service):
                     ca='IPA',
                     profile=dogtag.DEFAULT_PROFILE,
                     dns=[self.fqdn],
-                    post_command=cmd)
+                    post_command=cmd
+                )
             finally:
                 if prev_helper is not None:
                     certmonger.modify_ca_helper('IPA', prev_helper)