SSL: fixed c->read->ready handling in ngx_ssl_recv().

If c->read->ready was reset, but later some data were read from a socket
buffer due to a call to ngx_ssl_recv(), the c->read->ready flag should
be restored if not all data were read from OpenSSL buffers (as kernel
won't notify us about the data anymore).

More details are available here:
http://mailman.nginx.org/pipermail/nginx/2013-November/041178.html

src/event/ngx_event_openssl.c

@@ -965,6 +965,7 @@ ngx_ssl_recv(ngx_connection_t *c, u_char *buf, size_t size)
             size -= n;
 
             if (size == 0) {
+                c->read->ready = 1;
                 return bytes;
             }
 
@@ -974,6 +975,10 @@ ngx_ssl_recv(ngx_connection_t *c, u_char *buf, size_t size)
         }
 
         if (bytes) {
+            if (c->ssl->last != NGX_AGAIN) {
+                c->read->ready = 1;
+            }
+
             return bytes;
         }