Merge branch 'issue/initialize-members-sequential-ionformation' into 'master'

Initialize all members of SequentialInformation

See merge request core/dune-istl!545

dune/istl/paamg/pinfo.hh

@@ -92,8 +92,8 @@ namespace Dune
       SequentialInformation(const SequentialInformation&)
       {}
     private:
-      MPICommunicator comm_;
-      GlobalLookupIndexSet gli;
+      MPICommunicator comm_{};
+      GlobalLookupIndexSet gli{};
     };