Disable WCONHIST/GRAT non-existence test

Keyword WCONHIST always supports GRAT control mode, even when
defaulted.  The default value (zero) might not be very useful in a
simulation case but it's supported nonetheless.

opm/parser/eclipse/IntegrationTests/ScheduleCreateFromDeck.cpp

@@ -105,7 +105,8 @@ BOOST_AUTO_TEST_CASE(WellTesting) {
             BOOST_CHECK(  prop3.hasProductionControl(WellProducer::ORAT));
             BOOST_CHECK(  prop3.hasProductionControl(WellProducer::GRAT));
         }
-        BOOST_CHECK( !well2->getProductionProperties(8).hasProductionControl(WellProducer::GRAT));
+
+        // BOOST_CHECK( !well2->getProductionProperties(8).hasProductionControl(WellProducer::GRAT));
     }