keeping owned dofs sets, which was clared too early

src/field/DistributedField.cpp

@@ -663,7 +663,6 @@ namespace gmshfem::field
 
     _sharedDofs.clear();
     _subdomainInterfaceDofs.clear();
-    _ownedDofs.clear();
     _toSend.clear();
     _toRead.clear();