cfg: remove unused "mode"

Mode is not being used in the code, and is therefore removed from the config.

motion_capture_tracking/config/cfg.yaml

@@ -5,11 +5,6 @@
  # Specify the hostname or IP of the computer running the motion capture software
  hostname: "130.149.82.37"
 
- # Use "motionCapture" to disable custom rigid body tracking (to rely on the vendor's software)
- # Use "libRigidBodyTracker" for custom frame-by-frame tracking, in which you need to define 
- # marker_configurations, dynamics_configurations, and rigid_bodies below.
- mode: "libRigidBodyTracker"
-
  # The information will always be broadcasted via tf2
  # Specify additional settings for the /poses topic here
  topics: