Revert "avformat/img2dec: reduce bmppipe probe score"

This seems not needed anymore

This reverts commit 321c3cd1.

Found-by: carl

libavformat/img2dec.c

@@ -585,7 +585,7 @@ static int bmp_probe(AVProbeData *p)
         return 0;
 
     if (!AV_RN32(b + 6)) {
-        return AVPROBE_SCORE_EXTENSION - 1; // lower than extension as bmp pipe has bugs
+        return AVPROBE_SCORE_EXTENSION + 1;
     } else {
         return AVPROBE_SCORE_EXTENSION / 4;
     }