package imagemagick: add ffmpeg dependency so auto-detection will find it

src/imagemagick.mk

@@ -10,7 +10,7 @@ $(PKG)_SUBDIR   := ImageMagick-$($(PKG)_VERSION)
 $(PKG)_FILE     := ImageMagick-$($(PKG)_VERSION).tar.bz2
 $(PKG)_WEBSITE  := http://www.imagemagick.org/
 $(PKG)_URL      := http://ftp.nluug.nl/ImageMagick/$($(PKG)_FILE)
-$(PKG)_DEPS     := gcc libtool lcms tiff freetype jasper jpeg libpng fftw bzip2 openexr zlib pthreads
+$(PKG)_DEPS     := gcc bzip2 ffmpeg fftw freetype jasper jpeg lcms libpng libtool openexr pthreads tiff zlib
 
 define $(PKG)_UPDATE
     wget -q -O- 'http://ftp.nluug.nl/ImageMagick/?C=M;O=D' | \