Update .env.example - disable debug logging and fixed provider by default

Author: adg-flare

.env.example

@@ -1,7 +1,7 @@
-# Log level - remove to disable debug logging
-LOG_LEVEL=debug 
+# Log level - enable debug logging
+# LOG_LEVEL=debug 
 
 # Optional
 VALUE_PROVIDER_CLIENT_PORT=3101
 # Set to "fixed" to use a fixed provider, leave empty for ccxt provider
-VALUE_PROVIDER_IMPL="fixed"
+# VALUE_PROVIDER_IMPL="fixed"