Msmtp configuration error

Hi.

After trying to install and configure msmtp by using this guide (https://www.techrapid.uk/2017/04/send-email-with-msmtp-on-openwrt.html and its source https://vigasdeep.com/2014/05/06/installing-and-configuring-msmtp/), I'm getting these error lines at PuTTy:

Error relocating /usr/lib/libgnutls.so.30: explicit_bzero: symbol not found
Error relocating /usr/lib/libgnutls.so.30: getrandom: symbol not found

My msmtprc file is like this:

# Example for a system wide configuration file

# A system wide configuration file is optional.
# If it exists, it usually defines a default account.
# This allows msmtp to be used like /usr/sbin/sendmail.
account default

# The SMTP smarthost
host smtp.gmail.com

# Use TLS on port 465
port 587
tls on
tls_starttls on
tls_certcheck off

# Construct envelope-from addresses of the form "user@oursite.example"
#auto_from on
#maildomain oursite.example

# Syslog logging with facility LOG_MAIL instead of the default LOG_USER
syslog LOG_MAIL
auth login
user xxxxx@gmail.com
password yyyyyyyyyyyyyyy
from xxxxx@gmail.com

What are these errors and how to solve this?

Upgrade libnettle to the latest version (3.4.1-1).