http2 adaptor leaks qdr_connection_t and qdr_http2_connection_t objects when connector and server deleted at the same time

[ganeshmurthy]

A http2 server has a http2Connector to a server. When a management delete is run on the connector at the same time that the server is killed, the http2 adaptor leaks qdr_connection_t and qdr_http2_connection_t objects

The following reproducer is courtesy of @kgiusti . You will see the leaked connections number increasing slowly

class Http2AdaptorIssue627Test(TestCase):
    """
    Test connector delete via managment during server connection loss
    """
    CONNECTOR_TYPE = 'io.skupper.router.httpConnector'
    PROTOCOL_VERSION = "HTTP2"

    @classmethod
    def setUpClass(cls):
        super(Http2AdaptorIssue627Test, cls).setUpClass()

        cls.test_name = 'HTTPAdaptorIssue627'

        config = Qdrouterd.Config([('router', {'mode': 'interior',
                                               'id': 'INTA'}),
                                   ('listener', {'role': 'normal',
                                                 'port': cls.tester.get_port()}),
                                   ('address', {'prefix': 'closest',   'distribution': 'closest'}),
                                   ('address', {'prefix': 'multicast', 'distribution': 'multicast'}),
                                   ])
        cls.INTA = cls.tester.qdrouterd('INTA', config, wait=True)

    def start_server(self, connector_port):
        server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        server.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
        server.settimeout(TIMEOUT)
        server.bind(("", connector_port))
        server.listen(1)
        return server

    def test_01_issue_627(self):
        """Reproduce Issue #627"""
        mgmt = self.INTA.management

        for i in range(3000):
            connector_name = f"Connector_{self.test_name}_{i}"
            van_address = f"closest/{self.test_name}/{i}"
            connector_port = self.tester.get_port()


            cmd = ["test-receiver",
                   "-a", self.INTA.addresses[0],
                   "-c", "0"]
            rx = self.popen(cmd, expect=-15)

            cmd = ["test-sender",
                   "-a", self.INTA.addresses[0],
                   "-c", "0"]
            tx = self.popen(cmd, expect=-15)

            with self.start_server(connector_port) as server:
                attributes = {'address': van_address,
                              'host': '127.0.0.1',
                              'port': connector_port,
                              'protocolVersion': self.PROTOCOL_VERSION}
                mgmt.create(type=self.CONNECTOR_TYPE,
                            name=connector_name,
                            attributes=attributes)
                # server_conn, _ = server.accept()

                self.INTA.wait_address(van_address, subscribers=1)

                # server_conn.shutdown(socket.SHUT_RDWR)
                # server_conn.close()

            mgmt.delete(type=self.CONNECTOR_TYPE, name=connector_name)

            self.INTA.wait_address_unsubscribed(van_address, timeout=15.0)

            tx.terminate()
            tx.wait()
            tx.teardown()
            rx.terminate()
            rx.wait()
            rx.teardown()

            results = mgmt.query(type='io.skupper.router.connection').results
            print(f"Test cycle {i} complete {len(results)}!", flush=True)