Stream: delete proxy connection timer after SSL handshake.

The timer remained active and could drop active SSL connection.

src/stream/ngx_stream_proxy_module.c

diff --git a/src/stream/ngx_stream_proxy_module.c b/src/stream/ngx_stream_proxy_module.c
index ea142e7..6800500 100644
--- a/src/stream/ngx_stream_proxy_module.c
+++ b/src/stream/ngx_stream_proxy_module.c
@@ -759,6 +759,10 @@
             u->peer.save_session(&u->peer, u->peer.data);
         }
 
+        if (pc->write->timer_set) {
+            ngx_del_timer(pc->write);
+        }
+
         ngx_stream_proxy_init_upstream(s);
 
         return;