Missing template clone() in configmgr dconf mode

...that could cause infinite recursion, e.g. when an erroneously modified
/org.openoffice.ucb.Hierarchy/Entry template (which recursively has children of
the same template type) is later used to instantiate a new set member.

Change-Id: I7b9e55fa1c92979aed98b9f23f4432600afffed4
Reviewed-on: https://gerrit.libreoffice.org/54023Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>

configmgr/source/dconf.cxx

@@ -938,6 +938,7 @@ void readDir(
                                 << templ);
                         continue;
                     }
+                    member = member->clone(true);
                     break;
                 default:
                     assert(false); // cannot happen