Handle 0 frame_mod

src/zm_eventstream.cpp

@@ -1058,7 +1058,8 @@ void EventStream::runStream() {
           // but what if we are skipping frames? We need the distance from the last frame sent
           // Also, what about reverse? needs to be absolute value
 
-          delta = abs(next_frame_data->offset - last_frame_data->offset) /frame_mod;
+          delta = abs(next_frame_data->offset - last_frame_data->offset);
+          if (frame_mod) delta /= frame_mod;
           Debug(2, "New delta: %fs from last frame offset %fs - next_frame_offset %fs",
                 FPSeconds(delta).count(),
                 FPSeconds(last_frame_data->offset).count(),