Fixing some compile issues for alpine and centos, also fix endian issue for FLASH hashslot prefix (#722)

*fix for rocksdb centos compile fail

* fix alpine compile

* fix hashslot enumerate

* update alpine docker to latest version

* fix mac build, use big endian for expire prefix

* use endian.h for expires too

pkg/docker/Dockerfile_Alpine

@@ -1,4 +1,4 @@
-FROM alpine:3.12
+FROM alpine:3.18
 # add our user and group first to make sure their IDs get assigned consistently, regardless of whatever dependencies get added
 RUN addgroup -S -g 1000 keydb && adduser -S -G keydb -u 999 keydb
 RUN mkdir -p /etc/keydb