introducing upstream changes in stable

autogen.sh

@@ -46,7 +46,10 @@ if [ -s configure ]; then
     exit 0
   fi
 elif [ "$dev_setup" != true ]; then
-  echo "A development environment was not created."
+  echo "If you are looking to install a stable version of libsodium,"
+  echo "please do not run arbitrary, undocumented commands."
+  echo
+  echo "Installation instructions are available at https://libsodium.org"
   exit 0
 fi
 
@@ -97,7 +100,7 @@ if [ "$overwrite_config" = false ]; then
   fi
 fi
 
-[ "$update_config" = true ] && [ -z "$DO_NOT_UPDATE_CONFIG_SCRIPTS" ] &&
+[ "$update_config" = true ] &&
   command -v curl >/dev/null 2>&1 && {
   echo "Downloading config.guess and config.sub..."