SpeedscopeRenderer: delete jsonrender comment
SpeedscopeRenderer: delete jsonrender comment

This commit deletes the jsonrenderer comment in the SpeedscopeRenderer
implementation; the source file is obviously not named jsonrenderer.

joerick/pyinstrument,joerick/pyinstrument,joerick/pyinstrument,joerick/pyinstrument,joerick/pyinstrument,joerick/pyinstrument