toolbox/make-all-gc-eligible.sh: remove girocco.gcsig section
Instead of removing the gitweb.lastreceive setting, remove the
entire girocco.gcsig section to make a project eligible for gc.
With the addition of the gc "signature" hashes to determine whether
or not gc may be skipped (because there's nothing to do), if any
of the previous values for the signature hashes are missing, gc
will never be skipped.
By removing the girocco.gcsig section instead of the gitweb.lastreceive
section, the value of the lastreceive timestamp is preserved while
still forcing gc to take place at the next scheduled gc interval.
Signed-off-by: Kyle J. McKay <mackyle@gmail.com>