tdf#129210 don't assert with clear on already cleared mutex

reset it after load completes, seeing as the comment suggests
that's why the clear exists in the first place

Change-Id: I3af633c5a1f99b5d0dd754c21e220c6c94b66634
Reviewed-on: https://gerrit.libreoffice.org/84784
Tested-by: Jenkins
Reviewed-by: Xisco Faulí <xiscofauli@libreoffice.org>
diff --git a/dbaccess/source/core/dataaccess/databasedocument.cxx b/dbaccess/source/core/dataaccess/databasedocument.cxx
index 30ffe0c..d5e9e43 100644
--- a/dbaccess/source/core/dataaccess/databasedocument.cxx
+++ b/dbaccess/source/core/dataaccess/databasedocument.cxx
@@ -685,6 +685,7 @@ void SAL_CALL ODatabaseDocument::recoverFromFile( const OUString& i_SourceLocati

        aGuard.clear(); // (load has an own guarding scheme)
        load( aMediaDescriptor.getPropertyValues() );
        aGuard.reset();

        // Without a controller, we are unable to recover the sub components, as they're always tied to a controller.
        // So, everything else is done when the first controller is connected.