[core,nla]: Fix using password from redirection

If a client reconnects on redirection process and uses NLA authentication,
the client was using the old password because it wasn't setting
usePassword to false.

With this commit the client will use the new password.

libfreerdp/core/nla.c

@@ -391,6 +391,8 @@ static BOOL nla_client_setup_identity(rdpNla* nla)
 			        (const WCHAR*)settings->RedirectionPassword,
 			        settings->RedirectionPasswordLength / sizeof(WCHAR) - 1) < 0)
 				return FALSE;
+
+			usePassword = FALSE;
 		}
 
 		if (settings->RestrictedAdminModeRequired)