Change ordering for better layer caching

Dockerfile

@@ -1,18 +1,19 @@
 FROM alpine:latest as build
 
 WORKDIR /sslh
-COPY . /sslh
 
 RUN apk add gcc libconfig-dev make musl-dev pcre2-dev perl
+
+COPY . /sslh
 RUN make sslh-select && strip sslh-select
 
 FROM alpine:latest
 
-COPY --from=build "/sslh/sslh-select" "/usr/local/bin/sslh"
-
 RUN apk --no-cache add libconfig pcre2 iptables ip6tables libcap
 
 RUN adduser sslh --shell /bin/sh --disabled-password
+
+COPY --from=build "/sslh/sslh-select" "/usr/local/bin/sslh"
 RUN setcap cap_net_bind_service,cap_net_raw+ep /usr/local/bin/sslh
 
 COPY "./container-entrypoint.sh" "/init"