quickstart: Remove reference to `python hello.py`
quickstart: Remove reference to `python hello.py`

Fix #1826

pallets/flask,karlw00t/flask,fkazimierczak/flask,dawran6/flask,wldtyp/flask,hyunchel/flask,adrianmoisey/cptdevops,drewja/flask,karlw00t/flask,drewja/flask,pallets/flask,fkazimierczak/flask,adrianmoisey/cptdevops,tristanfisher/flask,auready/flask,tristanfisher/flask,Endika/flask,pallets/flask,mitsuhiko/flask,drewja/flask,antsar/flask,antsar/flask,hyunchel/flask,fkazimierczak/flask,auready/flask,mitsuhiko/flask,Endika/flask,wldtyp/flask,dawran6/flask