Regression with 0.9.3 with reset sequence

[matejsp]

We noticed that with 0.9.3 there is a regression with handling of sequence reset.

We reset sequence on start of service but then we don't on reconnect.
Before 0.9.3 it was possible with:

func (c *FixConnector) ToAdmin(message *quickfix.Message, sessionID quickfix.SessionID) {
	log.Println("ToAdmin", fix_msg.ToReadableString(message))
	if message.IsMsgTypeOf(string(fix_enum.MsgType_LOGON)) {
	    if c.resetSeqNum {
		message.SetResetSeqNumFlag(true)
		c.resetSeqNum = false
	    }
	}
}

Regression is in the following PR because it moved ToAdmin after handling of reset sequence not before like it used to be.
https://github.com/quickfixgo/quickfix/pull/635/files
#625

Not sure why it was required to move processing after ToAdmin handler.
We cannot change session settings since it returns readonly like we used for getting username

    settings := c.settings.SessionSettings()[sessionID]
    username, err := settings.Setting("Username")

I can provide a PR but would be good to know reason for moving ToAdmin call.