Segfault when delete_event called on invalid socket

Perhaps we should initialize the event to NULL? why isn't it NULL
already.

Change-Id: Ice1d16547021607d329571aa8ba3dbe3d4aed104
Reviewed-on: http://review.couchbase.org/13122
Reviewed-by: Sergey Avseyev <sergey.avseyev@gmail.com>
Reviewed-by: Trond Norbye <trond.norbye@gmail.com>
Reviewed-by: Mordechai Nunberg <mnunberg@haskalah.org>
Tested-by: Sergey Avseyev <sergey.avseyev@gmail.com>

src/server.c

@@ -260,12 +260,9 @@ libcouchbase_error_t libcouchbase_failout_server(libcouchbase_server_t *server,
 
     server->connected = 0;
 
-    if (error != LIBCOUCHBASE_CONNECT_ERROR) {
-        server->instance->io->delete_event(server->instance->io,
-                                           server->sock, server->event);
-    }
-
     if (server->sock != INVALID_SOCKET) {
+        server->instance->io->delete_event(server->instance->io, server->sock,
+                                           server->event);
         server->instance->io->close(server->instance->io, server->sock);
         server->sock = INVALID_SOCKET;
     }