Provide sane error message for missing certificate

[https://www.google.com/accounts/o8/id?id=AItOawkPb0RtPyicSdU7pLcv1UrX-yCh-YjkOwU]

Current trunk produces this:

$ sudo bcfg2 -q -v -n
Failed to download probes from bcfg2: [Errno 185090050] _ssl.c:328: error:0B084002:x509 certificate routines:X509_load_cert_crl_file:system lib

This can be improved to be more user-friendly.

[solj]

Are you seeing a traceback anywhere for this? I can't seem to reproduce that error message. It seems like this is coming straight from openssl.

[https://www.google.com/accounts/o8/id?id=AItOawkPb0RtPyicSdU7pLcv1UrX-yCh-YjkOwU]

I've copied bcfg2.conf from server to client as-is. After I setup ca, the error is gone.

[solj]

Full error message:

# bcfg2 -vqn                                                                                                  
Server failure: [Errno 185090050] _ssl.c:340: error:0B084002:x509 certificate routines:X509_load_cert_crl_file:system lib
Failed to download probes from bcfg2
[Errno 185090050] _ssl.c:340: error:0B084002:x509 certificate routines:X509_load_cert_crl_file:system lib

Can also be reproduced by adding ca = /foo to bcfg2.conf.

[solj]

Fixed in 4d87c5c2022c01dc171a276ca1aefde3e3fe43da.