I don't think it will converge in 0 steps for a lower force criterion - your output file shows that the max forces in step 0 are about 0.04 eV/Ang. So, for 0.05 as criterion yes, but for a smaller value it should go on, and I don't see any output showing that it doesn't. But in general, I would not expect that a system like this exhibits any strong changes in positions. And besides - if you would want to optimize it, just optimize the C-C bond length in pure graphene (2 atoms) which is a lot faster, before you make the supercell.