[server] bump prod audio quality from V6 to V4

The audio quality is painful and i dont think its the source because our encoding would not otherwise make a 5 min song 3MB
testing this to see if itll make it audibly less compressed?
Sorry for your disk space kasi but in fairness it was worse than this before encoding was even a thing ;)

UwuRadio.Server/constants.json

@@ -6,6 +6,6 @@
   "CacheFolder": "DL_CACHE",
   "IngestFolder": "ingest",
   "AudioFormat": "mp3",
-  "AudioQScale": "6",
+  "AudioQScale": "4",
   "AudioNormIntegrated": -16
 }