Added support for rhel-8.* to OpenResty build script

[ajaypvictor]

With this change, the openresty build should not exit for future releases of 8.x .. we have validated the modified script on both rhel 8.2 and rhel 8.3,

RHEL-8.2:

[root@edacac8b097b /]# cat /etc/os-release
NAME="Red Hat Enterprise Linux"
VERSION="8.2 (Ootpa)"
ID="rhel"
ID_LIKE="fedora"
VERSION_ID="8.2"
PLATFORM_ID="platform:el8"
PRETTY_NAME="Red Hat Enterprise Linux 8.2 (Ootpa)"
ANSI_COLOR="0;31"
CPE_NAME="cpe:/o:redhat:enterprise_linux:8.2:GA"
HOME_URL="https://www.redhat.com/"
BUG_REPORT_URL="https://bugzilla.redhat.com/"

REDHAT_BUGZILLA_PRODUCT="Red Hat Enterprise Linux 8"
REDHAT_BUGZILLA_PRODUCT_VERSION=8.2
REDHAT_SUPPORT_PRODUCT="Red Hat Enterprise Linux"
REDHAT_SUPPORT_PRODUCT_VERSION="8.2"
[root@edacac8b097b /]#
[root@edacac8b097b /]# resty -e 'print("hello, world")'
hello, world
[root@edacac8b097b /]#

RHEL-8.3

[root@ec9eb517abfb /]# uname -m
s390x
[root@ec9eb517abfb /]# cat /etc/os-release
NAME="Red Hat Enterprise Linux"
VERSION="8.3 (Ootpa)"
ID="rhel"
ID_LIKE="fedora"
VERSION_ID="8.3"
PLATFORM_ID="platform:el8"
PRETTY_NAME="Red Hat Enterprise Linux 8.3 (Ootpa)"
ANSI_COLOR="0;31"
CPE_NAME="cpe:/o:redhat:enterprise_linux:8.3:GA"
HOME_URL="https://www.redhat.com/"
BUG_REPORT_URL="https://bugzilla.redhat.com/"

REDHAT_BUGZILLA_PRODUCT="Red Hat Enterprise Linux 8"
REDHAT_BUGZILLA_PRODUCT_VERSION=8.3
REDHAT_SUPPORT_PRODUCT="Red Hat Enterprise Linux"
REDHAT_SUPPORT_PRODUCT_VERSION="8.3"
[root@ec9eb517abfb /]# resty -e 'print("hello, world")'
hello, world
[root@ec9eb517abfb /]#

Please review: @aborkar-ibm

[cwsolee]

This repo doesn't plan to accept PR and in this case, we intentionally only list the rhel version that we've validated. Feel free to customize our script to your own need.