[bugfix] add missing header

dune/istl/test/vectortest.hh

@@ -15,6 +15,7 @@
  * bound: any feature that is tested here is part of the dune-istl vector interface.
  */
 
+#include <dune/common/exceptions.hh>
 #include <dune/common/test/iteratortest.hh>
 
 namespace Dune
@@ -179,4 +180,4 @@ namespace Dune
   }
 }  // namespace Dune
 
-#endif
\ No newline at end of file
+#endif