Before this commit, it was not possible to center a button using the
editor option 'align center'.
It is because, using document.execCommand(), the Chrome browser doesnt
want apply 'text-align: center' on nodes with centered children. And
the buttons have the boostrap class '.btn' which adds text-align:
center.
So the hack here is disabling the text-align property from the '.btn'
class during the execution of document.execCommand().
task-2423935
closesodoo/odoo#65566
X-original-commit: d4f38c344360713287eed22872614f46dec7e0f6
Signed-off-by: Quentin Smetz (qsm) <qsm@odoo.com>