[BUG] git_push.sh can incorrectly set git config without recovery method

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• What's the version of OpenAPI Generator used?
• Have you search for related issues/PRs?
• What's the actual output vs expected output?
• [Optional] Bounty to sponsor the fix (example)

Description

If git_push.sh is run without supplying any one of git_host git_user_id git_repo_id
then a dummy string is substituted and this dummy string is used to set the git remote.

If on a subsequent run these parameters are supplied correctly then the git remote is not updated.

openapi-generator version

4.3.1

OpenAPI declaration file content or url

Occurs regardless of input file

Generation Details

git_push.sh appears in many (all?) supplied examples and is created when generating python, python-flask and many other languages.

Steps to reproduce

$ /bin/sh ./git_push.sh
…
remote: The project you were looking for could not be found.
fatal: repository 'https://github.com/GIT_USER_ID/GIT_REPO_ID.git/' not found
…
$ /bin/sh ./git_push.sh wing328 openapi-pestore-perl "minor update" "gitlab.com"
…
remote: The project you were looking for could not be found.
fatal: repository 'https://agile.nat.bt.com/gitlab/GIT_USER_ID/GIT_REPO_ID.git/' not found
$ git remote -v
origin https://github.com/GIT_USER_ID/GIT_REPO_ID.git (fetch)
origin https://github.com/GIT_USER_ID/GIT_REPO_ID.git (push)

Related issues/PRs

None found

Suggest a fix

If any one of git_host git_user_id git_repo_id are not supplied then output an ERROR message and stop rather than the current behaviour of outputting an INFO message and continuing.

Start by locating the git_push.sh script in the supplied examples and reviewing how git_host, git_user_id, and git_repo_id are handled. Reproduce the two command examples, then verify that missing parameters stop with an ERROR and that a later valid run does not retain the dummy remote; check the resulting git remote -v output.