fix(web): use a distinct salt for TOTP authentication

If TOTP is enabled for a user, it will be disabled until the user
configure it again, which will generate a new private salt.

SoObjects/Appointments/SOGoCalendarComponent.m

@@ -234,7 +234,7 @@
 
   tags = [NSArray arrayWithObjects: @"DTSTAMP", @"DTSTART", @"DTEND", @"DUE", @"EXDATE", @"EXRULE", @"RRULE", @"RECURRENCE-ID", nil];
   uid = [[component uid] asCryptedPassUsingScheme: @"ssha256"
-                                         withSalt: [[settings userSalt] dataUsingEncoding: NSASCIIStringEncoding]
+                                         withSalt: [[settings userPublicSalt] dataUsingEncoding: NSASCIIStringEncoding]
                                       andEncoding: encHex
                                           keyPath: nil];