Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.1.1
I think there is a bug with gnutls-cli 3.4.10 with Emacs 24.5.1 since
every time I write :
M-x list-packages an error message come up 'gnutls.c [0] error: ......
TLS connection terminated'