EclProblem: print "checking conservativeness" messages in debug mode

ebos/eclproblem.hh

@@ -898,7 +898,9 @@ public:
             // the right thing (i.e., the mass change inside the whole reservoir must be
             // equivalent to the fluxes over the grid's boundaries plus the source rates
             // specified by the problem)
+            std::cout << "checking conservativeness of solution\n";
             this->model().checkConservativeness(/*tolerance=*/-1, /*verbose=*/true);
+            std::cout << "solution is sufficiently conservative\n";
         }
 #endif // NDEBUG