Fixed handling of the ready flag with kqueue.

There is nothing to do more when recv() has returned 0,
so we should drop the flag.

src/os/unix/ngx_readv_chain.c

@@ -129,6 +129,7 @@ ngx_readv_chain(ngx_connection_t *c, ngx_chain_t *chain)
                                   "%d available bytes", rev->available);
 #endif
 
+                    rev->ready = 0;
                     rev->eof = 1;
                     rev->available = 0;
                 }

src/os/unix/ngx_recv.c

@@ -80,6 +80,7 @@ ngx_unix_recv(ngx_connection_t *c, u_char *buf, size_t size)
                      * even if kqueue reported about available data
                      */
 
+                    rev->ready = 0;
                     rev->eof = 1;
                     rev->available = 0;
                 }