configure: Check if libwebp compilation will succeed.

configure

@@ -4810,7 +4810,9 @@ enabled libvpx            && {
     enabled libvpx_vp9_decoder && { check_lib2 "vpx/vpx_decoder.h vpx/vp8dx.h" "vpx_codec_vp9_dx" -lvpx || disable libvpx_vp9_decoder; }
     enabled libvpx_vp9_encoder && { check_lib2 "vpx/vpx_encoder.h vpx/vp8cx.h" "vpx_codec_vp9_cx VP9E_SET_SVC" -lvpx || disable libvpx_vp9_encoder; } }
 enabled libwavpack        && require libwavpack wavpack/wavpack.h WavpackOpenFileOutput  -lwavpack
-enabled libwebp           && require_pkg_config libwebp webp/encode.h WebPGetEncoderVersion
+enabled libwebp           && require_pkg_config libwebp webp/encode.h WebPGetEncoderVersion &&
+                             { check_code cc webp/encode.h "WebPPicture wp; wp.use_argb++" ||
+                               die "ERROR: libwebp too old."; }
 enabled libx264           && require libx264 x264.h x264_encoder_encode -lx264 &&
                              { check_cpp_condition x264.h "X264_BUILD >= 118" ||
                                die "ERROR: libx264 must be installed and version must be >= 0.118."; }