fix polymer in flow bug.

opm/polymer/PolymerInflow.cpp

@@ -72,6 +72,7 @@ namespace Opm
     {
         ScheduleConstPtr schedule = eclipseState->getSchedule();
         for (const auto& well : schedule->getWells(currentStep)) {
+            if (well->isInjector(currentStep)) {
                 WellInjectionProperties injection = well->getInjectionProperties(currentStep);
                 if (injection.injectorType == WellInjector::WATER) {
                     WellPolymerProperties polymer = well->getPolymerProperties(currentStep);
@@ -81,6 +82,7 @@ namespace Opm
                 }
             }
         }
+    }
 
     /// Constructor.
     /// @param[in]  deck     Input deck expected to contain WPOLYMER.