SSL: overcame possible buffer over-read in ngx_ssl_error().

It appeared that ERR_error_string_n() cannot handle zero buffer size well enough
and causes over-read.

The problem has also been fixed in OpenSSL:
https://git.openssl.org/?p=openssl.git;h=e5c1361580d8de79682958b04a5f0d262e680f8b
1 file changed
tree: 9d874386904774bc44128631fb426b4e03363b62
  1. auto/
  2. conf/
  3. contrib/
  4. docs/
  5. misc/
  6. src/
  7. .hgtags