progress: use %d to format ints instead of %s
Due to behavioral changes between '% Ns' and '% Nd' this has some
unfortunate extra dancing. I'm not sure of a better way to solve this
problem.
Differential Revision: https://phab.mercurial-scm.org/D2226
ERROR: FIXME: This is a known failure of filelog.size for data starting with \1\n
OK.