[FIX] developer: fix bad documentation of --unaccent

In the CLI, `--unaccent` try to enable PostgreSQL unaccent extention
when odoo is responsible to create new database(s).

closes #6236

Signed-off-by: Antoine Vandevenne (anv) <anv@odoo.com>

Author: ryv-odoo

content/developer/reference/cli.rst

@@ -278,7 +278,7 @@ Database
 
 .. option:: --unaccent
 
-   Use the unaccent function provided by the database when available.
+   Try to enable the unaccent extension when creating new databases
 
 .. _reference/cmdline/server/emails: