rpc/test/client_test: Make chan not block forever.

Change-Id: I053a14d7aae4096a41c6dd8e3acab9c855b10357
diff --git a/runtime/internal/rpc/test/client_test.go b/runtime/internal/rpc/test/client_test.go
index a42aca4..af0cd1b 100644
--- a/runtime/internal/rpc/test/client_test.go
+++ b/runtime/internal/rpc/test/client_test.go
@@ -539,7 +539,11 @@
 
 	// Make sure we failed because we really did close the connection
 	// with our filter
-	<-ch
+	select {
+	case <-ch:
+	case <-time.After(10 * time.Second):
+		t.Errorf("timeout waiting for chan")
+	}
 }
 
 func TestStartCallSecurity(t *testing.T) {