Check mission climb always on current mission item (#22230)

* mission_base: reset inactivation index when user set a new mission index, or mission is reset.

* mission_base: check Climb required always on current mission item

src/modules/navigator/mission.cpp

@@ -141,6 +141,9 @@ Mission::set_current_mission_index(uint16_t index)
 			set_mission_items();
 		}
 
+		// User has actively set new index, reset.
+		_inactivation_index = -1;
+
 		return true;
 	}