next_reneighbor should be initialized in setup_pre_exchange()

src/GRANULAR/fix_pour.cpp

@@ -371,6 +371,13 @@ void FixPour::init()
   }
 }
 
+/* ---------------------------------------------------------------------- */
+
+void FixPour::setup_pre_exchange()
+{
+  next_reneighbor = update->ntimestep + 1;
+}
+
 /* ----------------------------------------------------------------------
    perform particle insertion
 ------------------------------------------------------------------------- */