development: remove MISSION_CHANGED

This proposed message is no longer required as the plan is to impelement
MISSION_CHECKSUM instead.

message_definitions/v1.0/common.xml

@@ -5269,7 +5269,7 @@
       <extensions/>
       <field type="uint8_t" name="mission_type" enum="MAV_MISSION_TYPE">Mission type.</field>
     </message>
-    <!-- Note, id 52 reserved for MISSION_CHANGED message (development.xml) -->
+    <!-- Note, id 53 reserved for MISSION_CHECKSUM message (development.xml) -->
     <message id="54" name="SAFETY_SET_ALLOWED_AREA">
       <description>Set a safety zone (volume), which is defined by two corners of a cube. This message can be used to tell the MAV which setpoints/waypoints to accept and which to reject. Safety areas are often enforced by national or competition regulations.</description>
       <field type="uint8_t" name="target_system">System ID</field>

message_definitions/v1.0/development.xml

@@ -253,14 +253,6 @@
       <field type="uint8_t" name="param_result" enum="PARAM_ACK">Result code.</field>
     </message>
     <!-- mission protocol enhancements -->
-    <message id="52" name="MISSION_CHANGED">
-      <description>A broadcast message to notify any ground station or SDK if a mission, geofence or safe points have changed on the vehicle.</description>
-      <field type="int16_t" name="start_index">Start index for partial mission change (-1 for all items).</field>
-      <field type="int16_t" name="end_index">End index of a partial mission change. -1 is a synonym for the last mission item (i.e. selects all items from start_index). Ignore field if start_index=-1.</field>
-      <field type="uint8_t" name="origin_sysid">System ID of the author of the new mission.</field>
-      <field type="uint8_t" name="origin_compid" enum="MAV_COMPONENT">Component ID of the author of the new mission.</field>
-      <field type="uint8_t" name="mission_type" enum="MAV_MISSION_TYPE">Mission type.</field>
-    </message>
     <message id="53" name="MISSION_CHECKSUM">
       <description>Checksum for the current mission, rally point or geofence plan, or for the "combined" plan (a GCS can use these checksums to determine if it has matching plans).
         This message must be broadcast with the appropriate checksum following any change to a mission, geofence or rally point definition