Add missing header file to GasLiftGroupInfo.cpp

GasLiftGroupInfo.cpp did not include "config.h" which caused HAVE_MPI
to be undefined causing the file to be compiled with
Dune::Communication<No_Comm> instead of with
Dune::Communication<MPI_Comm>. Which later caused linking problems with files
that used MPI.

tests/test_glift1.cpp

@@ -178,7 +178,8 @@ BOOST_AUTO_TEST_CASE(G1)
         iteration_idx,
         well_model.phaseUsage(),
         deferred_logger,
-        well_state
+        well_state,
+        simulator->vanguard().grid().comm()
     };
     GLiftSyncGroups sync_groups;
     GasLiftSingleWell glift {*std_well, *(simulator.get()), summary_state,