[Bug] invalid memory address or nil pointer dereference proxy to openldap

[suse-coder]

Describe the bug

When I moved from the 4.0.0-rc1 to the 4.0.0 version I get this invalid memory address or nil pointer dereference error in my proxy pod. It seems that with 4.1.0 this was fixed but I cant upgrade due to new bug in 4.1.0 (#2130) :

{"level":"debug","service":"proxy","authenticator":"oidc","path":"/ocs/v1.php/cloud/capabilities","time":"2026-01-22T09:56:24Z","line":"github.com/opencloud-eu/opencloud/services/proxy/pkg/middleware/oidc_auth.go:204","message":"successfully authenticated request"}
{"level":"debug","service":"proxy","time":"2026-01-22T09:56:24Z","line":"github.com/opencloud-eu/opencloud/services/proxy/pkg/userroles/oidcroles.go:187","message":"refreshing roles ids"}
{"level":"error","service":"proxy","error":"{\"id\":\"go.micro.server\",\"code\":500,\"detail\":\"panic recovered: runtime error: invalid memory address or nil pointer dereference\",\"status\":\"Internal Server Error\"}","time":"2026-01-22T09:56:25Z","line":"github.com/opencloud-eu/opencloud/services/proxy/pkg/userroles/oidcroles.go:211","message":"Failed to list all roles"}
{"level":"error","service":"proxy","request-id":"afa7b120-80ca-4d4f-95fc-d2cf86053a02","userid":"005db44a-0b16-4968-a823-1301c6baed00","error":"{\"id\":\"go.micro.server\",\"code\":500,\"detail\":\"panic recovered: runtime error: invalid memory address or nil pointer dereference\",\"status\":\"Internal Server Error\"}","time":"2026-01-22T09:56:25Z","line":"github.com/opencloud-eu/opencloud/services/proxy/pkg/userroles/oidcroles.go:78","message":"Error mapping role names to role ids"}
{"level":"error","service":"proxy","error":"{\"id\":\"go.micro.server\",\"code\":500,\"detail\":\"panic recovered: runtime error: invalid memory address or nil pointer dereference\",\"status\":\"Internal Server Error\"}","time":"2026-01-22T09:56:25Z","line":"github.com/opencloud-eu/opencloud/services/proxy/pkg/middleware/account_resolver.go:192","message":"Could not get user roles"}
{"level":"info","service":"proxy","proto":"HTTP/1.1","request-id":"afa7b120-80ca-4d4f-95fc-d2cf86053a02","traceid":"9b46e23f1463c6203f667b1862025782","remote-addr":"172.20.113.117","method":"GET","status":500,"path":"/ocs/v1.php/cloud/capabilities","duration":827.409219,"bytes":0,"time":"2026-01-22T09:56:25Z","line":"github.com/opencloud-eu/opencloud/services/proxy/pkg/middleware/accesslog.go:34","message":"access-log"}

Steps to reproduce

1. update to 4.0.0
2. login via sso (keycloak) -> error
3. see error in proxy pod

I would like to go to 4.1.0 but cant due to bug: #2130

Expected behavior

No exception should load openldap infos

Additional context

Add any other context about the problem here.