component/ffmpeg: build lame with slapos curses

to prevent from using system packages when libcurses-dev is installed

component/ffmpeg/buildout.cfg

@@ -3,6 +3,7 @@ extends =
   ../bzip2/buildout.cfg
   ../libpng/buildout.cfg
   ../patch/buildout.cfg
+  ../ncurses/buildout.cfg
   ../pkgconfig/buildout.cfg
   ../zlib/buildout.cfg
   ../xorg/buildout.cfg
@@ -86,6 +87,10 @@ md5sum = 8e9866ad6b570c6c95c8cba48060473f
 configure-options =
   --disable-static
   --disable-gtktest
+environment =
+  PKG_CONFIG=${pkgconfig:location}/bin/pkgconfig
+  PKG_CONFIG_PATH=${ncurses:location}/lib/pkgconfig
+  LDFLAGS=-Wl,-rpath=${ncurses:location}/lib
 
 [opencore-amr]
 recipe = slapos.recipe.cmmi