Nginx simplified and faster dockerfile (#4268)

* Nginx simplified and faster dockerfile

Now use ubuntu 18:10.
Web servers use functionalities from new kernels.

* Nginx use ubuntu latest

* Revert to ubutnu 18.10

frameworks/C/nginx/nginx.dockerfile

@@ -2,12 +2,9 @@ FROM ubuntu:18.10
 
 ARG DEBIAN_FRONTEND=noninteractive
 
-RUN apt-get update -yqq && apt-get install -yqq software-properties-common > /dev/null
-RUN LC_ALL=C.UTF-8 add-apt-repository -y ppa:ondrej/nginx-mainline
-#RUN add-apt-repository -y ppa:nginx/development
 RUN apt-get update -yqq
 RUN apt-get install -y nginx-light
 
 ADD ./ ./
 
-CMD nginx -c /nginx.conf
+CMD nginx -c /nginx.conf