fix: var API_AUDIO_CONVERTER with default value

Author: DavidsonGomes

.env.example

@@ -249,8 +249,8 @@ S3_USE_SSL=true
 # S3_REGION=eu-south
 
 # Evolution Audio Converter - Environment variables - https://github.com/EvolutionAPI/evolution-audio-converter
-API_AUDIO_CONVERTER=http://localhost:4040/process-audio
-API_AUDIO_CONVERTER_KEY=429683C4C977415CAAFCCE10F7D57E11
+# API_AUDIO_CONVERTER=http://localhost:4040/process-audio
+# API_AUDIO_CONVERTER_KEY=429683C4C977415CAAFCCE10F7D57E11
 
 # Define a global apikey to access all instances.
 # OBS: This key must be inserted in the request header to create an instance.