Is my salary haram after attesting that I've never been convicted by a court of law, when I was fined for entering a train platform without a ticket?

When joining a government organization, there was a question while filling the attestation form that have you ever been convicted by a court of law for any offence. I wrote no. Actually I had been fined by an rpf court of law for entering into the railway platform without platform ticket. During the time of filling the application form somebody told me it's just a petty case already closed so no need to mention. So I did it. Will my salary be halal or haram?