build: Make sure we have the scripts submodule
Update scripts

A bug was fixed in the gst-plugins-bad build script

Change-Id: I1f353029ffddef42a7eec815a8aea602a55d4af2
exported symbols: removed g_io_stream_is_datagram

Change-Id: Ida0c0185c45a3ec5cdf1a6859c9a2eeb94160f1c