lavf/img2dec: Increase detection score of jpgs without EOI.

Also increases the score for large jpeg files.
Fixes autodetection for the file from mpv issue 3973.

libavformat/img2dec.c

@@ -755,6 +755,8 @@ static int jpeg_probe(AVProbeData *p)
 
     if (state == EOI)
         return AVPROBE_SCORE_EXTENSION + 1;
+    if (state == SOS)
+        return AVPROBE_SCORE_EXTENSION / 2 + 1;
     return AVPROBE_SCORE_EXTENSION / 8;
 }