configure.ac: bump required GLib to 2.26
configure.ac: bump required GLib to 2.26

krieger-od/gstreamer,justinjoy/gstreamer,krichter722/gstreamer,lubosz/gstreamer,krieger-od/gstreamer,StreamUtils/gstreamer,mparis/gstreamer,jpxiong/gstreamer,Lachann/gstreamer,lovebug356/gstreamer,krieger-od/gstreamer,lubosz/gstreamer,StreamUtils/gstreamer,lubosz/gstreamer,krichter722/gstreamer,lubosz/gstreamer,cfoch/gstreamer,krieger-od/gstreamer,surround-io/gstreamer,jpakkane/gstreamer,krichter722/gstreamer,surround-io/gstreamer,krieger-od/gstreamer,shelsonjava/gstreamer,ensonic/gstreamer,lovebug356/gstreamer,ensonic/gstreamer,cfoch/gstreamer,mparis/gstreamer,collects/gstreamer,Lachann/gstreamer,shelsonjava/gstreamer,mparis/gstreamer,mparis/gstreamer,jpxiong/gstreamer,ensonic/gstreamer,shelsonjava/gstreamer,centricular/gstreamer,shelsonjava/gstreamer,cfoch/gstreamer,cablelabs/gstreamer,justinjoy/gstreamer,jpxiong/gstreamer,centricular/gstreamer,centricular/gstreamer,surround-io/gstreamer,justinjoy/gstreamer,justinjoy/gstreamer,collects/gstreamer,cablelabs/gstreamer,ensonic/gstreamer,surround-io/gstreamer,StreamUtils/gstreamer,justinjoy/gstreamer,surround-io/gstreamer,shelsonjava/gstreamer,jpxiong/gstreamer,collects/gstreamer,krichter722/gstreamer,cablelabs/gstreamer,lovebug356/gstreamer,collects/gstreamer,lovebug356/gstreamer,cablelabs/gstreamer,ensonic/gstreamer,jpakkane/gstreamer,jpakkane/gstreamer,jpakkane/gstreamer,krichter722/gstreamer,cfoch/gstreamer,mparis/gstreamer,StreamUtils/gstreamer,cfoch/gstreamer,collects/gstreamer,centricular/gstreamer,jpxiong/gstreamer,cablelabs/gstreamer,lovebug356/gstreamer,centricular/gstreamer,Lachann/gstreamer,lubosz/gstreamer,Lachann/gstreamer,StreamUtils/gstreamer,Lachann/gstreamer,jpakkane/gstreamer