when generating a CSR in the control panel, don't set empty attributes

Same as in a52c56e5.

Fixes #1338.

CHANGELOG.md

 CHANGELOG
 =========
 
+In Development
+--------------
+
+Control Panel:
+
+* Installing your own TLS/SSL certificate had been broken since v0.24 because the new version of openssl became stricter about CSR generation parameters.
+
 v0.26b (January 25, 2018)
 -------------------------
 

management/ssl_certificates.py

@@ -556,7 +556,7 @@ def create_csr(domain, ssl_key, country_code, env):
                 "openssl", "req", "-new",
                 "-key", ssl_key,
                 "-sha256",
-                "-subj", "/C=%s/ST=/L=/O=/CN=%s" % (country_code, domain)])
+                "-subj", "/C=%s/CN=%s" % (country_code, domain)])
 
 def install_cert(domain, ssl_cert, ssl_chain, env, raw=False):
 	# Write the combined cert+chain to a temporary path and validate that it is OK.