Don't clone base64 repository at first build, use a static version of Base64.h (not modified since many years)

Patch from Nguyễn Gia Phong

scripts/setup.sh

@@ -8,11 +8,6 @@ if [ ! -d lib/pugixml ] ; then
     popd
 fi
 
-# Base64
-if [ ! -d lib/base64 ] ; then
-    git clone https://gist.github.com/f0fd86b6c73063283afe550bc5d77594.git lib/base64
-fi
-
 # uPDFParser
 if [ ! -d lib/updfparser ] ; then
     git clone git://soutade.fr/updfparser.git lib/updfparser

scripts/update_lib.sh

@@ -12,9 +12,6 @@ pushd lib/pugixml
 git pull origin latest
 popd
 
-# Base64
-# Nothing to do
-
 # uPDFParser
 pushd lib/updfparser
 git pull origin master