Two parameters for OC.dialogs.alert, otherwise one will be "undefined".

Also fixed missing translation.

Before the click on a single file delete icon fired two different handlers - one of them is for multiple deletion only

skip update if the recipient is the same user as the owner, otherwise we run in a infinite loop for group shares

LDAP: user exists check on getHome, otherwise check will be performed with wrong configs on a multi LDAP server setup.