It probably is fair use, yes. It's less than twenty seconds long; it isn't of very high quality; it could be construed as being used in a parody of its source; it isn't being sold; etc. However, it isn't credited.
Fair use cases can get pretty far into gray areas, though I'd say the use of this recording is defensible.
Also, since this is a public domain piece of music, it probably wouldn't be very hard at all to find a CC-licensed recording. (If a longer recording is to be used.)