Navigator: remove MIS_LTRMIN_ALT param, and use new param MIS_LND_ABRT_ALT for landing abort

MIS_LTRMIN_ALt was used to limit the go-to altitude of a LOITER_TO_ALT (not the exit altitude,
but the altitude that the vehicle went to to fly to WP), and during landing abort to climb to
at least this altitude. The min entry altitude of LOITER_TO_ALT I remove with this commit, while
for the min alt during abort I added the new parameter MIS_LND_ABRT_ALT.

Signed-off-by: Silvan Fuhrer <silvan@auterion.com>

src/modules/navigator/mission_params.c

@@ -72,21 +72,6 @@ PARAM_DEFINE_FLOAT(MIS_TAKEOFF_ALT, 2.5f);
  */
 PARAM_DEFINE_INT32(MIS_TKO_LAND_REQ, 0);
 
-/**
- * Minimum Loiter altitude
- *
- * This is the minimum altitude the system will always obey. The intent is to stay out of ground effect.
- * set to -1, if there shouldn't be a minimum loiter altitude
- *
- * @unit m
- * @min -1
- * @max 80
- * @decimal 1
- * @increment 0.5
- * @group Mission
- */
-PARAM_DEFINE_FLOAT(MIS_LTRMIN_ALT, -1.0f);
-
 /**
  * Maximal horizontal distance from home to first waypoint
  *
@@ -172,3 +157,16 @@ PARAM_DEFINE_FLOAT(MIS_YAW_ERR, 12.0f);
  * @group Mission
  */
 PARAM_DEFINE_FLOAT(MIS_PD_TO, 5.0f);
+
+/**
+ * Landing abort min altitude
+ *
+ * Minimum altitude above landing point that the vehicle will climb to after an aborted landing.
+ * Then vehicle will loiter in this altitude until further command is received.
+ * Only applies to fixed-wing vehicles.
+ *
+ * @unit m
+ * @min 0
+ * @group Mission
+ */
+PARAM_DEFINE_INT32(MIS_LND_ABRT_ALT, 30);