navd: check duration_typical before using (#27184)

check duration_typical

Co-authored-by: Kurt Nistelberger <kurt.nistelberger@gmail.com>

selfdrive/navd/navd.py

@@ -226,6 +226,10 @@ class RouteEngine:
     remaining = 1.0 - along_geometry / max(step['distance'], 1)
     total_distance = step['distance'] * remaining
     total_time = step['duration'] * remaining
+
+    if step['duration_typical'] is None:
+      total_time_typical = total_time
+    else:
       total_time_typical = step['duration_typical'] * remaining
 
     # Add up totals for future steps