Get the correct bit depth on FLAC (simon-r#23)

Recent ffprobe give the correct bit depth on 24 bit FLAC:
  Stream #0:0: Audio: flac, 192000 Hz, stereo, s32 (24 bit)

dr14tmeter/read_metadata.py

@@ -362,11 +362,15 @@ def __read_stream_info(self, data_txt, track):
         track['channel'] = re.search(
             "^\s*([\S][\s|\S]*[\S])\s*$", fmt[2], re_flags).group(1)
 
-        m = re.search("(\d+)", fmt[3], re_flags)
+        m = re.search("\((\d+) bit\)", fmt[3], re_flags)
         if m != None:
             track['bit'] = m.group(1)
         else:
-            track['bit'] = "16"
+            m = re.search("(\d+)", fmt[3], re_flags)
+            if m != None:
+                track['bit'] = m.group(1)
+            else:
+                track['bit'] = "16"
 
     def album_len(self):
         return len(self._tracks)