CURL failed: Problem with the SSL CA cert
When trying to install Nim using choosenim, I get the following curl error:

```
# curl https://nim-lang.org/choosenim/init.sh -sSf | sh
choosenim-init: Downloading choosenim-0.8.4_linux_amd64
/__w/choosenim/choosenim/src/choosenim.nim(350) choosenim
/__w/choosenim/choosenim/src/choosenim.nim(340) performAction
/__w/choosenim/choosenim/src/choosenim.nim(122) choose
/__w/choosenim/choosenim/src/choosenimpkg/channel.nim(37) getChannelVersion
/__w/choosenim/choosenim/src/choosenimpkg/download.nim(381) retrieveUrl
/__w/choosenim/choosenim/src/choosenimpkg/download.nim(72) checkCurl
Error: unhandled exception: CURL failed: Problem with the SSL CA cert (path? access rights?) [AssertionDefect]
```

My system:

```
# cat /etc/issue
Debian GNU/Linux 9 \n \l
# uname -a
Linux nas 4.9.0-11-amd64 #1 SMP Debian 4.9.189-3+deb9u2 (2019-11-11) x86_64 GNU/Linux
```