Identities using tilde specified in config are not loaded

In the latest version of sshd, the library fails to load any identities specified in the .ssh/config file if they use tilde in their path (e.g. ~/.ssh/id_test).

This seems to be a regression from https://github.com/apache/mina-sshd/pull/353 because the resolveIdentityFilePath method inside HostConfigEntry is no longer called.