fix casing to suppress docker build warning

aptalca · somewatson · commit bb39404d819d · 2025-10-28T07:56:42.000Z
diff --git a/Dockerfile.complex b/Dockerfile.complex
@@ -1,7 +1,7 @@
 # syntax=docker/dockerfile:1
 
 ## Buildstage ##
-FROM ghcr.io/linuxserver/baseimage-alpine:3.19 as buildstage
+FROM ghcr.io/linuxserver/baseimage-alpine:3.19 AS buildstage
 
 RUN \
   echo "**** install packages ****" && \
