Handle nginx epel 1.20.1 changes (CentOS)

[sbesson]

Similarly to ome/ansible-role-nginx#11, the installation scripts might need to be reviewed in the light of the latest nginx updates:

• the nginx version shipped both by the EPEL repositories as well as the Nginx stable Yum repository is now at version 1.20.1
• nginx 1.20.1-2.el7 from the EPEL repository also includes changes to the default nginx.conf that might break the deployment using the current instructions. I would expect test_web.sh to fail however it looks like these tests are not executed in the GitHub actions.

In this repository, nginx is installed via EPEL as per

omeroweb-install/ansible/templates/centos7/deps.sh.j2

Lines 9 to 11 in 0f452b1

	yum -y install epel-release
	yum -y install unzip

. If the issue is confirmed, the potential mitigation options are:

• install nginx from the nginx-stable Yum repository. This might also require use yum install --disablerepo epel nginx in case epel has been installed. This is the current proposed approach used in the Ansible role
• investigate how to handle the new configuration shipped in nginx 1.20.1-2.el7 or replace nginx.conf by a custom template.