libcelt: configure: check for recent version.

configure

@@ -3103,7 +3103,7 @@ enabled frei0r     && { check_header frei0r.h || die "ERROR: frei0r.h header not
 enabled gnutls     && require_pkg_config gnutls gnutls/gnutls.h gnutls_global_init
 enabled libaacplus && require  "libaacplus >= 2.0.0" aacplus.h aacplusEncOpen -laacplus
 enabled libass     && require_pkg_config libass ass/ass.h ass_library_init
-enabled libcelt    && require libcelt celt/celt.h celt_decode -lcelt0
+enabled libcelt    && require libcelt celt/celt.h celt_decoder_create_custom -lcelt0
 enabled libdc1394  && require_pkg_config libdc1394-2 dc1394/dc1394.h dc1394_new
 enabled libdirac   && require_pkg_config dirac                          \
     "libdirac_decoder/dirac_parser.h libdirac_encoder/dirac_encoder.h"  \