For #1042, cover RTMP other codes

trunk/src/utest/srs_utest_protostack.cpp

@@ -2476,8 +2476,10 @@ VOID TEST(ProtoStackTest, CoverAll)
 
         io.in_buffer.append(&io.out_buffer);
         SrsCommonMessage* msg = NULL;
-        HELPER_ASSERT_SUCCESS(r.recv_message(&msg));
-        srs_freep(msg);
+        SrsAcknowledgementPacket* pkt = NULL;
+        HELPER_ASSERT_SUCCESS(r.expect_message(&msg, &pkt));
+        EXPECT_EQ(1024, pkt->sequence_number);
+        srs_freep(msg); srs_freep(pkt);
     }
 }