Fix server certificate verification failed – manual trust CA Cert

Example do as root:

echo -n | openssl s_client -connect git.kolab.org:443 | sed -ne '/-BEGIN CERTIFICATE-/,/-END CERTIFICATE-/p'| tee '/usr/local/share/ca-certificates/git_kolab_org.crt'

echo -n | openssl s_client -connect vserver2.cadena-it.com:8083 | sed -ne '/-BEGIN CERTIFICATE-/,/-END CERTIFICATE-/p'| tee '/usr/local/share/ca-certificates/vserver2.cadena-it.com.crt'
update-ca-certificates