configure: add missing swscale to avfilter when sr filter is enabled

Signed-off-by: James Almer <jamrial@gmail.com>

configure

@@ -6826,7 +6826,7 @@ enabled signature_filter    && prepend avfilter_deps "avcodec avformat"
 enabled smartblur_filter    && prepend avfilter_deps "swscale"
 enabled spectrumsynth_filter && prepend avfilter_deps "avcodec"
 enabled spp_filter          && prepend avfilter_deps "avcodec"
-enabled sr_filter           && prepend avfilter_deps "avformat"
+enabled sr_filter           && prepend avfilter_deps "avformat swscale"
 enabled subtitles_filter    && prepend avfilter_deps "avformat avcodec"
 enabled uspp_filter         && prepend avfilter_deps "avcodec"
 enabled zoompan_filter      && prepend avfilter_deps "swscale"