Revert "Trying to fix the build dependencies"

This reverts commit 70b72352.

debian/jessie/Dockerfile

@@ -4,7 +4,6 @@ LABEL maintainer="ethitter"
 LABEL version="1.0"
 
 RUN echo "deb http://security.debian.org/ jessie/updates main" >> /etc/apt/sources.list
-RUN echo "deb http://httpredir.debian.org/debian/ jessie-backports main contrib non-free" >> /etc/apt/sources.list
 
 RUN apt-get update \
     && apt-get -yqqf --no-install-recommends install \
@@ -28,9 +27,8 @@ RUN apt-get update \
         libpcre3 \
         libpcre3-dev \
         libz-dev \
+        shellcheck \
         gnupg \
-    && apt-get -y --no-install-recommends install -t jessie-backports \
-        openssl \
         libssl-dev \
     && apt-get clean \
     && rm -rf /var/lib/apt/lists/*