fix unit tests: do not stub pthread_cond_wait

and fix the tests instead.
Some unit tests depend on pthread_cond_wait to work as expected.

src/lib/avoidance/ObstacleAvoidanceTest.cpp

@@ -49,6 +49,7 @@ public:
 	void SetUp() override
 
 	{
+		param_control_autosave(false);
 		param_reset_all();
 		pos_sp = Vector3f(1.f, 1.2f, 0.1f);
 		vel_sp = Vector3f(0.3f, 0.4f, 0.1f);

src/lib/collision_prevention/CollisionPreventionTest.cpp

@@ -42,6 +42,7 @@ class CollisionPreventionTest : public ::testing::Test
 public:
 	void SetUp() override
 	{
+		param_control_autosave(false);
 		param_reset_all();
 	}
 };

src/lib/parameters/ParameterTest.cpp

@@ -43,6 +43,7 @@ class ParameterTest : public ::testing::Test
 public:
 	void SetUp() override
 	{
+		param_control_autosave(false);
 		param_reset_all();
 	}
 };