Reset default values.

config/sample-production.engine-core.ini

@@ -59,11 +59,11 @@ output_device_4=""
 # Usually provided by your device
 sample_rate=""
 # Set to 0 to use the ALSA default. If using hardware directly (hw:0) start with 8192. Higher values give higher latency and lower CPU usage.
-alsa_buffer="0"
+alsa_buffer=""
 # Only used for buffered ALSA I/O, and affects latency. Probably not wanted for live audio. Defaults to "1"
-alsa_buffer_length="0"
+alsa_buffer_length=""
 # Set to 0 to use the ALSA default. Defaults to "0"
-alsa_periods="0"
+alsa_periods=""
 # Frame Size ("frame.audio.size"); Unclear if that's still required as it's not documented in Liquidsoap anymore.
 frame_size=""
 # Tentative frame duration in seconds, defaults to "0.04" (Float). This setting is used as a hint for the duration,