Workaround shouldn't be needed

src/freedombone-app-librevault

     apt-get -yq install autoconf automake libtool curl make unzip
 
     # A workaround which allows c++14 to be installed
-    sed -i 's|jessie|stretch|g' /etc/apt/sources.list
-    sed -i 's|stretch-backports|jessie-backports|g' /etc/apt/sources.list
-    apt-get update
     apt-get -yq install protobuf-compiler libprotobuf-dev
     apt-get -yq install g++ gcc-6 g++-6 libboost-all-dev libssl-dev
     apt-get -yq install qtbase5-dev libqt5svg5-dev libqt5websockets5-dev
     apt-get -yq install libsqlite3-dev qttools5-dev qttools5-dev-tools libnatpmp-dev
     apt-get -yq install gcc-6 g++-6 libboost-all-dev
-    sed -i 's|stretch|jessie|g' /etc/apt/sources.list
-    apt-get update
 
     if [ ! -d $INSTALL_DIR ]; then
         mkdir -p $INSTALL_DIR