Fix normalisation-pregain (#82)

Author: GioF71

README.md

@@ -346,6 +346,7 @@ Just be careful to use the tag you have built.
 
 Change Date|Major Changes
 ---|---
+2024-03-07|Fix switch for normalisation pregain (see [#81](https://github.com/GioF71/librespot-docker/issues/77))
 2023-12-20|Support docker --user mode (see [#77](https://github.com/GioF71/librespot-docker/issues/77))
 2023-10-06|Change ownership of volumes (see [#75](https://github.com/GioF71/librespot-docker/issues/75))
 2023-09-05|Clean Dockerfile (see [#73](https://github.com/GioF71/librespot-docker/issues/73))

app/bin/run-librespot.sh

@@ -216,7 +216,7 @@ if [ -n "$NORMALISATION_GAIN_TYPE" ]; then
 fi
 
 if [ -n "$NORMALISATION_PREGAIN" ]; then
-    CMD_LINE="$CMD_LINE --normalisation-pre-gain $NORMALISATION_PREGAIN"
+    CMD_LINE="$CMD_LINE --normalisation-pregain $NORMALISATION_PREGAIN"
 fi
 
 if [ -n "$NORMALISATION_THRESHOLD" ]; then