navigator: increase stack

The stack size was generally ok but seemed to get exhausted in the case
of a waypoint which is too far away and therefore exercises some more
code in the mission feasability checker.

Generally, we should have more margin in the navigator stack size
because there are a bunch of different code paths that can happen.

src/lib/matrix

@@ -1 +1 @@
-Subproject commit 34fccdd6806fbdf7635a6365d7ef112f3bbaab9a
+Subproject commit c387e52970b95af8f79795eaeb201e3dcba7284c

src/modules/navigator/navigator_main.cpp

@@ -673,7 +673,7 @@ Navigator::start()
 	_navigator_task = px4_task_spawn_cmd("navigator",
 					 SCHED_DEFAULT,
 					 SCHED_PRIORITY_DEFAULT + 5,
-					 1300,
+					 1600,
 					 (px4_main_t)&Navigator::task_main_trampoline,
 					 nullptr);