fix: 'java.util.HashSet' object has no attribute 'get' in Casa Script

[maduvena]

Same as https://github.com/GluuFederation/oxAuth/issues/1734

Describe the bug

12:12:43 INFO  PythonService.java:243 - Casa. authenticate for step 1
12:12:44 INFO  PythonService.java:243 - Casa. getAvailMethodsUser [otp, fido2]
12:12:44 INFO  PythonService.java:243 - Casa. getSuitableAcr. On mobile = True
12:12:44 INFO  PythonService.java:243 - Casa. getSuitableAcr. No mobile-friendly authentication method available for user user41
12:12:44 ERROR ExternalAuthenticationService.java:216 - AttributeError: 'java.util.HashSet' object has no attribute 'get'
org.python.core.PyException: AttributeError: 'java.util.HashSet' object has no attribute 'get'
        at org.python.core.Py.AttributeError(Py.java:176) ~[jython-standalone-2.7.3.jar:2.7.3b1-SNAPSHOT]
        at org.python.core.PyObject.noAttributeError(PyObject.java:965) ~[jython-standalone-2.7.3.jar:2.7.3b1-SNAPSHOT]
        at org.python.core.PyObject.__getattr__(PyObject.java:959) ~[jython-standalone-2.7.3.jar:2.7.3b1-SNAPSHOT]
        at org.python.pycode._pyx0.getSuitableAcr$24(casa.py:457) ~[?:?]
        at org.python.pycode._pyx0.call_function(casa.py) ~[?:?]
        at org.python.core.PyTableCode.call(PyTableCode.java:173) ~[jython-standalone-2.7.3.jar:2.7.3b1-SNAPSHOT]
        at org.python.core.PyBaseCode.call(PyBaseCode.java:187) ~[jython-standalone-2.7.3.jar:2.7.3b1-SNAPSHOT]
        at org.python.core.PyFunction.__call__(PyFunction.java:449) ~[jython-standalone-2.7.3.jar:2.7.3b1-SNAPSHOT]
        at org.python.core.PyMethod.__call__(PyMethod.java:171) ~[jython-standalone-2.7.3.jar:2.7.3b1-SNAPSHOT]
        at org.python.pycode._pyx0.authenticate$9(casa.py:189) ~[?:?]
        at org.python.pycode._pyx0.call_function(casa.py) ~[?:?]
        at org.python.core.PyTableCode.call(PyTableCode.java:173) ~[jython-standalone-2.7.3.jar:2.7.3b1-SNAPSHOT]

To Reproduce Steps to reproduce the behavior:

1. Register apple touch ID on casa
2. Register one more cred and turn on 2fa
3. Login using mobile phone so the isMobile criteria is fullfilled.
4. Unable to login, check the jans-auth logs

Expected behavior Login without error

Smartphone (please complete the following information):

• Device: [any iPhone] -isMobile and apple fido creds are required
• Browser [any]