fix assertPortList normalizing being too strict

The normalizing was updated with the output of the "docker port" command
in mind, but we're normalizing the "expected" output, which is passed
without the "->" in front of the mapping, causing some tests to fail;

    === RUN   TestDockerSuite/TestPortHostBinding
        --- FAIL: TestDockerSuite/TestPortHostBinding (1.21s)
            docker_cli_port_test.go:324: assertion failed: error is not nil: |:::9876!=[::]:9876|
    === RUN   TestDockerSuite/TestPortList
        --- FAIL: TestDockerSuite/TestPortList (0.96s)
            docker_cli_port_test.go:25: assertion failed: error is not nil: |:::9876!=[::]:9876|

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

integration-cli/docker_cli_port_test.go

@@ -161,7 +161,7 @@ func assertPortList(c *testing.T, out string, expected []string) error {
 	// of the CLI used an incorrect output format for mappings on IPv6 addresses
 	// for example, "80/tcp -> :::80" instead of "80/tcp -> [::]:80".
 	oldFormat := func(mapping string) string {
-		old := strings.Replace(mapping, "-> [", "-> ", 1)
+		old := strings.Replace(mapping, "[", "", 1)
 		old = strings.Replace(old, "]:", ":", 1)
 		return old
 	}