Fixes failure to retry script download. Tested and verified the issue is resolved.

The curl --retry-connrefused option is used with not instead of the --retry <num> option to add an extra type of failure to retry on, without --retry <num> it does not retry at all even on a connection refused. 

https://man.archlinux.org/man/curl.1.en
10 jobs for deimosian-master-patch-67154 in 76 minutes and 55 seconds (queued for 8 seconds)
Status Name Job ID Coverage
  Check
passed check #36614

00:00:14

 
  Build
passed build_long: [baseline iso] #36617
fast-single-thread

00:16:15

passed build_long: [baseline netboot] #36618
fast-single-thread

00:15:49

passed build_long: [releng iso] #36626
fast-single-thread

00:30:58

passed build_long: [releng netboot] #36622
fast-single-thread

00:29:26

passed build_short: [baseline bootstrap] #36615

00:12:07

passed build_short: [releng bootstrap] #36616

00:12:12

failed build_long: [releng iso] #36621
fast-single-thread

00:05:37

failed build_long: [releng iso] #36619
fast-single-thread

00:06:05

failed build_long: [releng netboot] #36620
fast-single-thread

00:06:11