Add support for host keys for non-22 ports

When not using the standard SSH port (22), the port is appended
to the hostname (in brackets) like so: "host" -> "[host]:1234"

Signed-off-by: Anders F Björklund <anders.f.bjorklund@gmail.com>
(cherry picked from commit 8794e8db1c)

pkg/bindings/connection.go

@@ -214,19 +214,23 @@ func sshClient(_url *url.URL, secure bool, passPhrase string, identity string) (
 		authMethods = append(authMethods, ssh.Password(string(pass)))
 	}
 
-	callback := ssh.InsecureIgnoreHostKey()
-	if secure {
-		key := terminal.HostKey(_url.Hostname())
-		if key != nil {
-			callback = ssh.FixedHostKey(key)
-		}
-	}
-
 	port := _url.Port()
 	if port == "" {
 		port = "22"
 	}
 
+	callback := ssh.InsecureIgnoreHostKey()
+	if secure {
+		host := _url.Hostname()
+		if port != "22" {
+			host = fmt.Sprintf("[%s]:%s", host, port)
+		}
+		key := terminal.HostKey(host)
+		if key != nil {
+			callback = ssh.FixedHostKey(key)
+		}
+	}
+
 	bastion, err := ssh.Dial("tcp",
 		net.JoinHostPort(_url.Hostname(), port),
 		&ssh.ClientConfig{