I'm not sure why we haven't removed the need for a license key in 5.1.2, but I'm sure we had a valid reason...
Perhaps not. Bug 10633, "Volcopy license should go away", was filed on this on September 28.
A fix was checked into the "main branch", but (perhaps because it was relatively late in the release cycle, or too late as in "the release already went out"), it's not in the 5.1[.x] or 5.2 code lines.