Since this option is soon to be used, this rename is a last tweek
to make it more logical to use since it will point to a single
upgrade dir most of the time.
closesodoo/odoo#44593
X-original-commit: 1c8e2809fb296abce6114b7da906d48a240df418
Signed-off-by: Xavier Dollé (xdo) <xdo@odoo.com>