Improve startup logging and logging consistency

Startup log:
- Add interface, port, and fileTransferPort fields to the "Hotline
  server started" line so operators can see what the server bound to.
- Resolve an empty -interface flag to 0.0.0.0 for display.

Levels:
- Demote the two Redis startup messages (ban management, cleared online
  users) from Info to Debug.

Consistency:
- Standardize the error field key to "err" (was "Err" in a few account
  handlers) and lowercase "Account" -> "account".
- Standardize the remote-address key to "remoteAddr" (was "RemoteAddr").
- Replace fmt.Sprintf in the tracker-registration message and string
  concatenation in the config-dir-init and ban-disconnect messages with
  structured fields; use the standard "err" key.
- Give the two bare rLogger.Error(err.Error()) file-transfer calls a
  descriptive message and an "err" field.

logger.go:
- Only attach the rotating lumberjack file writer when --log-file is set.
  An empty Filename made lumberjack write to a temp file by default.

1 files changed, 1 insertions, 1 deletions

diff --git a/hotline/client_conn.go b/hotline/client_conn.go
index 9ca93a7..c17ef35 100644
--- a/hotline/client_conn.go
+++ b/hotline/client_conn.go
@@ -176,7 +176,7 @@ func (cc *ClientConn) Disconnect() {
 	}
 
 	if err := cc.Connection.Close(); err != nil {
-		cc.Server.Logger.Debug("error closing client connection", "RemoteAddr", cc.RemoteAddr)
+		cc.Server.Logger.Debug("error closing client connection", "remoteAddr", cc.RemoteAddr)
 	}
 }