Fixed null pointer dereference in resolver (ticket #91).

The cycle->new_log.file may not be set before config parsing finished if
there are no error_log directive defined at global level.  Fix is to
copy it after config parsing.

Patch by Roman Arutyunyan.
diff --git a/src/core/ngx_resolver.c b/src/core/ngx_resolver.c
index 5a0ade7..5c51617 100644
--- a/src/core/ngx_resolver.c
+++ b/src/core/ngx_resolver.c
@@ -189,11 +189,6 @@
         uc->sockaddr = u.addrs->sockaddr;
         uc->socklen = u.addrs->socklen;
         uc->server = u.addrs->name;
-
-        uc->log = cf->cycle->new_log;
-        uc->log.handler = ngx_resolver_log_error;
-        uc->log.data = uc;
-        uc->log.action = "resolving";
     }
 
     return r;
@@ -876,6 +871,12 @@
     }
 
     if (uc->connection == NULL) {
+
+        uc->log = *r->log;
+        uc->log.handler = ngx_resolver_log_error;
+        uc->log.data = uc;
+        uc->log.action = "resolving";
+
         if (ngx_udp_connect(uc) != NGX_OK) {
             return NGX_ERROR;
         }