fix dockerfile

Dockerfile

@@ -1,4 +1,4 @@
-FROM docker.io/golang:alpine as builder
+FROM docker.io/golang:1.20-alpine as builder
 
 
 WORKDIR /src
@@ -7,15 +7,15 @@ ADD . /src
 
 RUN apk add build-base
 
-RUN cd server &&\
+RUN cd web3gw/server &&\
     GOOS=linux CGO_ENABLED=1 go build -o webproxy &&\
     chmod +x webproxy
 
 FROM alpine:3.14
 
 ARG SFTPGOBRANCH
 
-COPY --from=builder /src/server/webproxy /usr/bin/webproxy
+COPY --from=builder /src/web3gw/server/webproxy /usr/bin/webproxy
 
 COPY --from=builder /src/sftpgo.json /var/lib/sftpgo/sftpgo.json