Core: fixed error message on setsockopt(SO_REUSEPORT) failure.

The error is fatal when configuring a new socket, so the ", ignored" part
is not appropriate and was removed.

src/core/ngx_connection.c

diff --git a/src/core/ngx_connection.c b/src/core/ngx_connection.c
index be1e89c..392fc35 100644
--- a/src/core/ngx_connection.c
+++ b/src/core/ngx_connection.c
@@ -483,7 +483,7 @@
                     == -1)
                 {
                     ngx_log_error(NGX_LOG_EMERG, log, ngx_socket_errno,
-                                  "setsockopt(SO_REUSEPORT) %V failed, ignored",
+                                  "setsockopt(SO_REUSEPORT) %V failed",
                                   &ls[i].addr_text);
 
                     if (ngx_close_socket(s) == -1) {