Fix flaky test.

Author: ioquatix

test/async/container/controller.rb

@@ -196,7 +196,8 @@ def after(error = nil)
 
 			Process.kill(:HUP, pid)
 
-			expect(input.read(2)).to be == "I."
+			# The ordering between the old child writing "I" and the new child writing "." is timing-dependent (blue-green restart starts the new container before stopping the old one). Accept either order.
+			expect(input.read(2)).to (be == "I.").or(be == ".I")
 		end
 
 		it "exits gracefully when receiving SIGINT" do