Fixed cancel issue with stack actor.

Change-Id: I06651d5df8b636f8734192dbe8c2b0f3749f9e06
diff --git a/frc971/actors/stack_actor.cc b/frc971/actors/stack_actor.cc
index 4b31451..ac2d744 100644
--- a/frc971/actors/stack_actor.cc
+++ b/frc971/actors/stack_actor.cc
@@ -72,7 +72,9 @@
     message.Send();
   }
   DoProfile(bottom, -0.05, false);
+  if (ShouldCancel()) return true;
   DoProfile(bottom, 0.0, false);
+  if (ShouldCancel()) return true;
   aos::time::SleepFor(aos::time::Time::InMS(100));
 
   return true;