fix(jans-keycloak-link): not able to connect keycloack server

[manojs1978]

Describe the bug
A clear and concise description of what the bug is.

To Reproduce
Steps to reproduce the behavior:

1. install jans/flex nighlty
2. see error in jans-keycloak-link log

Expected behavior
should not get any error

Screenshots
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Desktop (please complete the following information):

• OS: ubuntu 22
• Browser [e.g. chrome, safari]
• Version [e.g. 22]
• DB mysql

Smartphone (please complete the following information):

• Device: [e.g. iPhone6]
• OS: [e.g. iOS8.1]
• Browser [e.g. stock browser, safari]
• Version [e.g. 22]

Additional context
Add any other context about the problem here.

25-01-2025 09:20:54.968 ERROR keycloak.link.timer.JansKeycloakLinkTimer JansKeycloakLinkTimer.java:214- not able to connect keycloack server : Unsupported grantType:  (only password and client_credentials are supported)
java.lang.IllegalArgumentException: Unsupported grantType:  (only password and client_credentials are supported)
        at org.keycloak.admin.client.Config.checkGrantType(Config.java:124)
        at org.keycloak.admin.client.KeycloakBuilder.grantType(KeycloakBuilder.java:78)
        at io.jans.keycloak.link.server.service.KeycloakService.getKeycloakInstance(KeycloakService.java:59)
        at io.jans.keycloak.link.server.service.KeycloakService$Proxy$_$$_WeldSubclass.getKeycloakInstance$$super(Unknown Source)
        at jdk.internal.reflect.GeneratedMethodAccessor74.invoke(Unknown Source)
        at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.base/java.lang.reflect.Method.invoke(Method.java:569)
        at org.jboss.weld.interceptor.proxy.TerminalAroundInvokeInvocationContext.proceedInternal(TerminalAroundInvokeInvocationContext.java:51)
        at org.jboss.weld.interceptor.proxy.AroundInvokeInvocationContext.proceed(AroundInvokeInvocationContext.java:78)
        at org.jboss.weld.probe.InvocationMonitor.monitor(InvocationMonitor.java:125)
        at jdk.internal.reflect.GeneratedMethodAccessor13.invoke(Unknown Source)
        at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.base/java.lang.reflect.Method.invoke(Method.java:569)
        at org.jboss.weld.interceptor.reader.SimpleInterceptorInvocation$SimpleMethodInvocation.invoke(SimpleInterceptorInvocation.java:73)
        at org.jboss.weld.interceptor.proxy.InterceptorMethodHandler.executeAroundInvoke(InterceptorMethodHandler.java:84)
        at org.jboss.weld.interceptor.proxy.InterceptorMethodHandler.executeInterception(InterceptorMethodHandler.java:72)

log.zip

[devrimyatar]

@manojs1978 @shekhar16 I did four installations and faced this issue only once.