Check load_robot_description argument (#86)

launch/planning_context.launch

@@ -8,7 +8,7 @@
   <arg name="robot_description" default="robot_description"/>
 
   <!-- Load universal robot description format (URDF) -->
-  <param name="$(arg robot_description)" command="$(find xacro)/xacro $(find franka_description)/robots/panda_arm.urdf.xacro hand:=$(arg load_gripper)" />
+  <param if="$(arg load_robot_description)" name="$(arg robot_description)" command="$(find xacro)/xacro $(find franka_description)/robots/panda_arm.urdf.xacro hand:=$(arg load_gripper)" />
 
   <!-- The semantic description that corresponds to the URDF -->
   <param name="$(arg robot_description)_semantic" command="$(find xacro)/xacro '$(find panda_moveit_config)/config/panda_arm_hand.srdf.xacro'" if="$(arg load_gripper)" />