Fixed the issue when slope limit was set to 90 degrees flax crashed.

I fixed the issue when slope limit was set to 90 degrees flax would commit suicide (crash) (: . I just changed the clamp limit from 90 to 89 degrees.

Source/Engine/Physics/Colliders/CharacterController.cpp

@@ -55,7 +55,7 @@ void CharacterController::SetHeight(const float value)
 
 void CharacterController::SetSlopeLimit(float value)
 {
-    value = Math::Clamp(value, 0.0f, 90.0f);
+    value = Math::Clamp(value, 0.0f, 89.0f);
     if (Math::NearEqual(value, _slopeLimit))
         return;