merge revision(s) r45271: [Backport #9592] [Backport #9671]

	* ext/openssl/ossl.c (ossl_make_error): check NULL for unknown
	  error reasons with old OpenSSL, and insert a colon iff formatted
	  message is not empty.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_1@45778 b2dd03c8-39d4-4d8f-98ff-823fe69b080e