message: remove trace of sync checkpoints from configure.ac
diff: @@ -111,13 +111,6 @@ AM_CONDITIONAL([HAVE_DOXYGEN], [test -n "$DOXYGEN"])
  AC_ARG_VAR(PYTHONPATH, Augments the default search path for python module files)
  -# Enable sync checkpoints
  -AC_ARG_ENABLE([checkpoints],
  - [AS_HELP_STRING([--disable-checkpoints],
  - [disable sync checkpoints (enabled by default)])],
  - [enable_checkpoints=$enableval],
  - [enable_checkpoints=yes])
  -
  AC_ARG_ENABLE([wallet],
  [AS_HELP_STRING([--disable-wallet],
  [disable wallet (enabled by default)])],
  @@ -1715,7 +1708,6 @@ esac
  echo
  echo "Options used to compile and link:"
  -echo " checkpoints = $enable_checkpoints"
  echo " with wallet = $enable_wallet"
  echo " with gui / qt = $bitcoin_enable_qt"
  if test x$bitcoin_enable_qt != xno; then
  