Remove unused include from sigar.c
Remove unused include from sigar.c

Change-Id: Ic2b0ee4cd4443d948d227d4f4d7cd483bd4e90d9
Reviewed-on: https://review.couchbase.org/c/sigar/+/166638
Tested-by: Build Bot <80754af91bfb6d1073585b046fe0a474ce868509@couchbase.com>
Reviewed-by: Jim Walker <1cd02e31b43620d7c664e038ca42a060d61727b9@couchbase.com>

couchbase/sigar,couchbase/sigar