Some people say were in this sentence, including me. But I hear many people saying was.
In other words, this is a sentence where you can use the subjunctive, if you are one of those people who like to use the subjunctive. But don't get too frustrated when you hear it with "was" -- and you will hear a lot of that.
Is it a subjunctive or not, despite people saying "was"/"were"?
I think we can say that it should use the subjunctive. But the subjunctive isn't required here in English, as it would be in certain other languages.
I try not to go around expressing the opinion that one should use the subjunctive, because that would just alienate the tons of people around me who don't use it. (But I can still have my private opinion!)