minor: Remove "js" (Javascript) from list of allowed languages in script config since it hasn't been present in OpenSimulator for a very long time (0.6 days)

One reason support was removed is that the external DLL that implemented Javascript stopped development.
Not sure how well this ever worked in OpenSimulator.
Not removing vb for now as this is directly supported by Mono (via vbnc compiler) though I strongly suspect it is also inoperable.