Event connect: don't penalize AF_INET6 connections.

Problems with setsockopt(TCP_NODELAY) and setsockopt(TCP_NOPUSH), as well
as sendfile() syscall on Solaris, are specific to UNIX-domain sockets.
Other address families, i.e. AF_INET and AF_INET6, are fine.

src/event/ngx_event_connect.c

diff --git a/src/event/ngx_event_connect.c b/src/event/ngx_event_connect.c
index 978f39b..e6ae656 100644
--- a/src/event/ngx_event_connect.c
+++ b/src/event/ngx_event_connect.c
@@ -84,7 +84,7 @@
 
     c->log_error = pc->log_error;
 
-    if (pc->sockaddr->sa_family != AF_INET) {
+    if (pc->sockaddr->sa_family == AF_UNIX) {
         c->tcp_nopush = NGX_TCP_NOPUSH_DISABLED;
         c->tcp_nodelay = NGX_TCP_NODELAY_DISABLED;