fix: SCHWED-3126 Add indef to header file

modules/mol/alg/src/molck.hh

+//------------------------------------------------------------------------------
+// This file is part of the OpenStructure project <www.openstructure.org>
+//
+// Copyright (C) 2008-2011 by the OpenStructure authors
+//
+// This library is free software; you can redistribute it and/or modify it under
+// the terms of the GNU Lesser General Public License as published by the Free
+// Software Foundation; either version 3.0 of the License, or (at your option)
+// any later version.
+// This library is distributed in the hope that it will be useful, but WITHOUT
+// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+// FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more
+// details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with this library; if not, write to the Free Software Foundation, Inc.,
+// 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+//------------------------------------------------------------------------------
+#ifndef OST_MOL_ALG_MOLCK_HH
+#define OST_MOL_ALG_MOLCK_HH
 
 #include <string>
 #include <ost/mol/entity_handle.hh>
@@ -80,3 +100,5 @@ void Molck(ost::mol::EntityHandle& ent,
 
 
 }}} // namespace
+
+#endif