configure.ac: Require latest gst-plugins-base for 'playsink'
configure.ac: Require latest gst-plugins-base for 'playsink'

ahmedammar/platform_external_gst_editing_services,luisbg/gst-editing-services,cfoch/ges,MathieuDuponchelle/PitiviGes,pitivi/gst-editing-services,cfoch/ges,volodymyrrudyi/gst-editing-services,pitivi/gst-editing-services,freesteph/gst-editing-services,pitivi/gst-editing-services,MathieuDuponchelle/PitiviGes,MathieuDuponchelle/PitiviGes,cfoch/gst-editing-services,volodymyrrudyi/gst-editing-services,cfoch/ges,ahmedammar/platform_external_gst_editing_services,volodymyrrudyi/gst-editing-services,freesteph/gst-editing-services,freesteph/gst-editing-services,cfoch/gst-editing-services,luisbg/gst-editing-services,cfoch/ges,cfoch/gst-editing-services,pitivi/gst-editing-services,cfoch/gst-editing-services,MathieuDuponchelle/PitiviGes