Add retry logic for web request

Sometimes the request to telegram API may fail because of temporary network issues:

Error response: reqwest::Error { kind: Request, url: Url { scheme: "https", cannot_be_a_base: false, username: "", password: None, host: Some(Domain("api.telegram.org")), port: None, path: "/botxxx/sendmessage", query: None, fragment: None }, source: hyper::Error(Connect, Ssl(Error { code: ErrorCode(5), cause: Some(Io(Os { code: 104, kind: ConnectionReset, message: "Connection reset by peer" })) }, X509VerifyResult { code: 0, error: "ok" })) }

Add retry logic to avoid unnecessary fallback to email