Use python3-mod-wsgi instead of mod_wsgi on CentOS8

This fixes a stack.sh execution error on CentOS8. We should use
python3-mod_wsgi instead of mod_wsgi since mod_wsgi is replaced by
python3-mod_wsgi. The following change may affect this issue.
https://git.centos.org/rpms/mod_wsgi/c/4a746b53e9e3fef74b227e016e785449160871b8?branch=c8s

Change-Id: I5344ecf519e1a79091b6158c2d711d09b21fae0c
Closes-Bug: #1885645
1 file changed