SPDY: fixed typo in log message.

src/http/ngx_http_spdy.c

diff --git a/src/http/ngx_http_spdy.c b/src/http/ngx_http_spdy.c
index b935b6f..9bd624c 100644
--- a/src/http/ngx_http_spdy.c
+++ b/src/http/ngx_http_spdy.c
@@ -943,7 +943,7 @@
     if (sc->processing >= sscf->concurrent_streams) {
 
         ngx_log_error(NGX_LOG_INFO, sc->connection->log, 0,
-                      "spdy concurrent streams excessed %ui", sc->processing);
+                      "spdy concurrent streams exceeded %ui", sc->processing);
 
         if (ngx_http_spdy_send_rst_stream(sc, sid, NGX_SPDY_REFUSED_STREAM,
                                           prio)