remove unused files from sslproxy folder, and fix build script for acme-nginx

dockerfiles/services/sslproxy/cetbot/Dockerfile

@@ -1,4 +0,0 @@
-FROM nginx:alpine
-
-COPY ./nginx.conf /etc/nginx/nginx.conf
-COPY ./hosts /etc/nginx/conf.d/

dockerfiles/services/sslproxy/testdata/_first.txt

@@ -1 +0,0 @@
-something elses.

dockerfiles/tasks/acme-nginx/build.sh

@@ -11,8 +11,7 @@ build() {
 build_test() {
   echo testing the image
   docker run --rm --entrypoint=ls $LOCAL_IMAGE -l /usr/local/bin | grep acme-nginx
-  docker run --rm -it $LOCAL_IMAGE -h
+  docker run --rm $LOCAL_IMAGE -h | grep 'usage: acme-nginx'
-  docker run --rm -it $LOCAL_IMAGE -h | grep 'usage: acme-nginx'
 }
 
 build_deploy() {