Fixed log action when using SSL certificates with variables.

When variables are used in ssl_certificate or ssl_certificate_key, a request
is created in the certificate callback to evaluate the variables, and then
freed.  Freeing it, however, updates c->log->action to "closing request",
resulting in confusing error messages like "client timed out ... while
closing request" when a client times out during the SSL handshake.

Fix is to restore c->log->action after calling ngx_http_free_request().

src/http/ngx_http_request.c

diff --git a/src/http/ngx_http_request.c b/src/http/ngx_http_request.c
index 684fabd..81b27a3 100644
--- a/src/http/ngx_http_request.c
+++ b/src/http/ngx_http_request.c
@@ -1043,12 +1043,14 @@
     }
 
     ngx_http_free_request(r, 0);
+    c->log->action = "SSL handshaking";
     c->destroyed = 0;
     return 1;
 
 failed:
 
     ngx_http_free_request(r, 0);
+    c->log->action = "SSL handshaking";
     c->destroyed = 0;
     return 0;
 }