Use external gzip to decompress hdlist.

On my machine, for a repository of 3000 packages, it goes from 7.8s real/7.6 user to 6.5 real/7.0 user
User time decreases because it seems to be faster by itself, real time probably because having another process allows them to run in parallel

1 files changed, 1 insertions, 0 deletions

diff --git a/genhdlist2 b/genhdlist2
index e6ca4f1..0dabfe0 100644
--- a/genhdlist2
+++ b/genhdlist2
@@ -172,6 +172,7 @@ sub build {
 	    archive => "$hdlist.tmp",
 	    compress => "gzip",
 	    uncompress => "gzip -d",
+	    extern => 1,
 	    comp_level => 9,
 	) or die "Can't create archive";
     }