Write tests for calling init() more than once

[jonkoops]

It is not possible to call init() more than once, an exception will be thrown if it is (see implementation under keycloak/keycloak#20722). This behavior is currently not covered by tests.

Under this issue a test must be written that will initialize a Keycloak JS instance twice, and assert that it does in fact throw an exception.

These tests must be added to the existing JavaScriptAdapterTest.

[Ehsanino82]

i write this pr for this issue keycloak/keycloak#21414

[jonkoops]

Thanks @Ehsanino82. The changes you made are not exactly what we need (see keycloak/keycloak#21414 (comment)). I've updated the issue to be more descriptive.

[KonarzewskiP]

Hey @jonkoops , can I take this issue?

[jonkoops]

Sure, go right ahead!