SPDY: alert about activated fake events instead of deleting them.

They refer to the same socket descriptor as our real connection, and
deleting them will stop processing of the connection.

Events of fake connections must not be activated, and if it happened there
is nothing we can do.  The whole processing should be terminated as soon as
possible, but it is not obvious how to do this safely.

src/http/ngx_http_spdy.c

diff --git a/src/http/ngx_http_spdy.c b/src/http/ngx_http_spdy.c
index 8522c6d..e7bebcc 100644
--- a/src/http/ngx_http_spdy.c
+++ b/src/http/ngx_http_spdy.c
@@ -2663,7 +2663,8 @@
     ev = fc->read;
 
     if (ev->active || ev->disabled) {
-        ngx_del_event(ev, NGX_READ_EVENT, 0);
+        ngx_log_error(NGX_LOG_ALERT, sc->connection->log, 0,
+                      "spdy fake read event was activated");
     }
 
     if (ev->timer_set) {
@@ -2677,7 +2678,8 @@
     ev = fc->write;
 
     if (ev->active || ev->disabled) {
-        ngx_del_event(ev, NGX_WRITE_EVENT, 0);
+        ngx_log_error(NGX_LOG_ALERT, sc->connection->log, 0,
+                      "spdy fake write event was activated");
     }
 
     if (ev->timer_set) {