fix missing memory cleanup for MPI tasks other than 1 (#1005)

This fixes #739

Author: rieder

src/amuse/community/gadget2/interface.cc

@@ -1453,6 +1453,7 @@ int check_counts_and_free(int *count, int length){
 #ifndef NOMPI
         MPI_Reduce(count, NULL, length, MPI_INT, MPI_SUM, 0, GADGET_WORLD);
 #endif
+        delete[] count;
         return 0;
     } else {
 #ifndef NOMPI