update connection readiness after SSL handshake,
this fixes mail proxy SSL connection hanging if level-triggered event is used

src/event/ngx_event_openssl.c

diff --git a/src/event/ngx_event_openssl.c b/src/event/ngx_event_openssl.c
index af54b50..40e3712 100644
--- a/src/event/ngx_event_openssl.c
+++ b/src/event/ngx_event_openssl.c
@@ -505,6 +505,9 @@
 
     if (n == 1) {
 
+        c->read->ready = 0;
+        c->write->ready = 1;
+
         if (ngx_handle_read_event(c->read, 0) == NGX_ERROR) {
             return NGX_ERROR;
         }