message: Adds inital value to safety_distance in panda_arm.xacro
diff: <?xml version='1.0' encoding='utf-8'?>
  <robot xmlns:xacro="http://www.ros.org/wiki/xacro" name="panda">
  - <xacro:macro name="panda_arm" params="arm_id:='panda' description_pkg:='franka_description' connected_to:='' xyz:='0 0 0' rpy:='0 0 0' safety_distance:=''">
  + <xacro:macro name="panda_arm" params="arm_id:='panda' description_pkg:='franka_description' connected_to:='' xyz:='0 0 0' rpy:='0 0 0' safety_distance:='0'">
  <xacro:unless value="${not connected_to}">
  <joint name="${arm_id}_joint_${connected_to}" type="fixed">
  <parent link="${connected_to}"/>
  