an number should not be formatted with decimals

This

$> git grep -n ', and had '
src/core/or/status.c:277:        "one was alive for %lf seconds, and had %lf unrecognized cells.",

gives

, and had 1.000000 unrecognized cells.

IMO something like ".0" is missing in the formatter string to count cells and not fractions of cells.