added implementation for Z3LpSolver::getValue() when z3_optimize is not available

src/storm/solver/Z3LpSolver.cpp

@@ -399,6 +399,10 @@ namespace storm {
                 throw storm::exceptions::NotImplementedException() << "This version of storm was compiled without Z3 or the version of Z3 does not support optimization. Yet, a method was called that requires this support.";
             }
             
+            storm::expressions::Expression Z3LpSolver::getValue(storm::expressions::Variable const& variable) const {
+                throw storm::exceptions::NotImplementedException() << "This version of storm was compiled without Z3 or the version of Z3 does not support optimization. Yet, a method was called that requires this support.";
+            }
+
             double Z3LpSolver::getContinuousValue(storm::expressions::Variable const&) const {
                 throw storm::exceptions::NotImplementedException() << "This version of storm was compiled without Z3 or the version of Z3 does not support optimization. Yet, a method was called that requires this support.";
             }