Fix patch "Parse port before trying by service name"

Fix patch "Parse port before trying by service name"

The patch broke parsing service names: number parsing failures
are hard errors which erase data, thus making impossible to
parse input as a string. Fix it by enabling soft (warning)
failures in the case of port number parsing.

Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org>