sample/http-server: fix parameter parsing argv[1] is currently unconditionally passed as the docroot to send_document_cb(). This is broken if any optional parameters are provided, such as -p <port>. Signed-off-by: David Disseldorp <ddiss@samba.org> (cherry picked from commit 7d71214e02646a31eede66ad5badf695a2ab2058)