try to replace https://raw.githubusercontent.com as one of the following proxys

 https://github.bajins.com
 https://raw.sevencdn.com 
 https://cdn.jsdelivr.net 
 https://raw.fastgit.org

you can find openresty formulas in /usr/local/Homebrew/Library/Taps/openresty/homebrew-brew/Formula
then edit the related openresty*.rb

grep -R "raw.githubusercontent.com" openresty*
sed -i -e 's/raw.githubusercontent.com/raw.fastgit.org/g' openresty*
grep -R "raw.fastgit" openresty*

for example:
https://raw.githubusercontent.com/openresty/openresty/master/patches/nginx-1.17.4-daemon_destroy_pool.patch
replace as https://raw.fastgit.org/openresty/openresty/master/patches/nginx-1.17.4-daemon_destroy_pool.patch

z$ curl https://raw.fastgit.org/openresty/openresty/master/patches/nginx-1.17.4-daemon_destroy_pool.patch

diff --git a/src/os/unix/ngx_daemon.c b/src/os/unix/ngx_daemon.c
index ab672110..f259af31 100644
--- a/src/os/unix/ngx_daemon.c
+++ b/src/os/unix/ngx_daemon.c
@@ -23,6 +23,8 @@ ngx_daemon(ngx_log_t *log)
         break;

     default:
+        /* just to make it ASAN or Valgrind clean */
+        ngx_destroy_pool(ngx_cycle->pool);
         exit(0);
     }