libtracker-data: use GPrivate if GLib >= 2.31
libtracker-data: use GPrivate if GLib >= 2.31

Since 2.31, GStaticPrivate is deprecated.

hoheinzollern/tracker,hoheinzollern/tracker,outofbits/tracker,hoheinzollern/tracker,hoheinzollern/tracker,hoheinzollern/tracker,outofbits/tracker,hoheinzollern/tracker,outofbits/tracker,outofbits/tracker,outofbits/tracker,hoheinzollern/tracker,outofbits/tracker,outofbits/tracker