Domain registration plugin is broken for Namecheap API

When adding an Namcheap account, the Domain registration plugin output:

Failed to save account : HTTP/1.1 400 Bad Request

This is due to an request malformation at line 542 and 544 of webmin/virtualmin-registrar/namecheap-type-lib.pl

There is an extra 2 bytes of content, namely "\r\n", that is not accounted for in Content-length header.

Please add, before line 539:

$data = "$data\r\n";

And change line 544 for :

&write_http_connection($h, "$data");