Fix Nav Config Typo

stretch_navigation/config/common_costmap_params.yaml

@@ -3,6 +3,6 @@ raytrace_range: 3.0
 robot_radius: 0.5
 inflation_radius: 0.55
 
-observational_sources: laser_scan_sensor
+observation_sources: laser_scan_sensor
 
 laser_scan_sensor: {sensor_frame: laser, data_type: LaserScan, topic: scan, marking: true, clearing: true}