configure: add dl to frei0r extralibs.

diff --git a/configure b/configure
index 4606b23..e207ed8 100755 (executable)
--- a/configure
+++ b/configure
@@ -1526,7 +1526,9 @@ cropdetect_filter_deps="gpl"
 delogo_filter_deps="gpl"
 drawtext_filter_deps="libfreetype"
 frei0r_filter_deps="frei0r dlopen strtok_r"
+frei0r_filter_extralibs='$ldl'
 frei0r_src_filter_deps="frei0r dlopen strtok_r"
+frei0r_src_filter_extralibs='$ldl'
 hqdn3d_filter_deps="gpl"
 ocv_filter_deps="libopencv"
 scale_filter_deps="swscale"