Make convert2rhel work with a proxy

Description of problem:
We are release locked to 8.3, we have updated to the latest Centos Kernel (4.18.0-240.22.1.el8_3.x86_64). The customer is using satellite and we have triple checked on another RHEL 8 machine registered the same way, that 8.3 AppStream and 8.3 BaseOS are sync'd and available. and we can see that the RHEL kernel*-4.18.0-240.22.1.el8_3.x86_64 is available and provides the same modules.

1. sed -i 's|releasever=8|releasever=8.3|' /usr/share/convert2rhel/configs/centos-8-x86_64.cfg

Customer has a proxy but configures it in the env as http_proxy and https_proxy as well as in /etc/yum.conf.

Version-Release number of selected component (if applicable):
convert2rhel-0.21-1.el7.noarch

Steps to Reproduce:
1. proxy configured with

1. export http_proxy=X.X.X.X
2. export https_proxy=X.X.X.X
3. echo "proxy=X.X.X.X" >> /etc/yum.conf
   2. workaround for 8.3 Centos:
4. sed -i 's|releasever=8|releasever=8.3|' /usr/share/convert2rhel/configs/centos-8-x86_64.cfg
   3. convert2rhel --debug --org="Richemont_International_SA" --activationkey $activationkey

Actual results:
CRITICAL - The following kernel modules are not supported in RHEL:
/lib/modules/4.18.0-240.22.1.el8_3.x86_64/kernel/net/netfilter/xt_TRACE.ko.xz
/lib/modules/4.18.0-240.22.1.el8_3.x86_64/kernel/drivers/input/rmi4/rmi_spi.ko.xz
/lib/modules/4.18.0-240.22.1.el8_3.x86_64/kernel/sound/drivers/mpu401/snd-mpu401.ko.xz
/lib/modules/4.18.0-240.22.1.el8_3.x86_64/kernel/drivers/media/usb/gspca/gspca_mr97310a.ko.xz
...
...<listed for every kernel module>

Expected results:
convert2rhel should allow for proxies in the environment. perhaps a --proxy option

An error message related to the connectivity to the repository or something more clear the issue is not related to kernel modules, but with the repository connection.

Additional info: