Revert "[fix] Allow empty users argument in app_add/removeaccess"

This reverts commit a4ab551447.

data/actionsmap/yunohost.yml

@@ -527,7 +527,7 @@ app:
                     nargs: "+"
                 -u:
                     full: --users
-                    nargs: "*"
+                    nargs: "+"
 
         ### app_removeaccess() TODO: Write help
         removeaccess:
@@ -541,7 +541,7 @@ app:
                     nargs: "+"
                 -u:
                     full: --users
-                    nargs: "*"
+                    nargs: "+"
 
         ### app_clearaccess()
         clearaccess:

lib/yunohost/app.py

@@ -542,7 +542,7 @@ def app_remove(auth, app):
     msignals.display(m18n.n('app_removed', app), 'success')
 
 
-def app_addaccess(auth, apps, users=[]):
+def app_addaccess(auth, apps, users):
     """
     Grant access right to users (everyone by default)
 
@@ -597,7 +597,7 @@ def app_addaccess(auth, apps, users=[]):
     return { 'allowed_users': new_users.split(',') }
 
 
-def app_removeaccess(auth, apps, users=[]):
+def app_removeaccess(auth, apps, users):
     """
     Revoke access right to users (everyone by default)