To set the upstream branch of your current branch back to origin/master,
use the -u|--set-upstream-to option of git branch :
git branch -u origin/master
The -u flag you passed to git push instructed git to link your current branch to remote branch origin/01-MyfeatureProductListing. git branch -u allows you to override this to any remote branch you want.
You can also use --unset-upstream to stop having git compare your local branch with a remote branch.
You can view the links between local branches and remote branches in the .git/config file of your local clone ; if you open this file with any text editor (gedit, notepad, vscode ... ), you should see several sections looking like :
[branch "mybranch"]
remote = origin
merge = refs/heads/01-MyfeatureProductListing
The above means local branch mybranch is set up to track origin/01-MyfeatureProductListing.
The -u option simply updates this section.
[edit] obviously : the -u option to git push is completely optional, if you want to push without setting or updating the remote tracked branch, just drop the -u option ...