www/tengine: video-thumbextractor is broken after r358176

In file included from src/ngx_http_video_thumbextractor_module.c:3:
src/ngx_http_video_thumbextractor_module_utils.c:5:10: fatal error: 'wand/magick_wand.h' file not found

^

/usr/bin/ld: cannot find -lMagickWand
cc: error: linker command failed with exit code 1 (use -v to see invocation)

PR: 185462 207547
Reported by: antoine (via exp-run)