message: build: Fix boost detection on Ubuntu ARM 18.04
  Update ax_boost_base.m4 to version in progress: autoconf-archive/autoconf-archive#198
  This is a temporary workaround for the problem in the 0.19.0 release;
  please pull in the upstream version when ready (see
  Tree-SHA512:
diff: # and this notice are preserved. This file is offered as-is, without any
  # warranty.
  -#serial 47
  +#serial 49
  # example boost program (need to pass version)
  m4_define([_AX_BOOST_BASE_PROGRAM],
  @@ -126,8 +126,14 @@ AC_DEFUN([_AX_BOOST_BASE_RUNDETECT],[
  [multiarch_libsubdir="lib/${host_cpu}-${host_os}"]
  )
  + dnl some arches may advertise a cpu type that doesn't line up with their
  + dnl prefix's cpu type. For example, uname may report armv7l while libs are
  + dnl installed to /usr/lib/arm-linux-gnueabihf. Try getting the compiler's
  + dnl value for an extra chance of finding the correct path.
  + libsubdirs="lib/`$CXX -dumpmachine 2>/dev/null` $libsubdirs"
  +
  dnl first we check the system location for boost libraries
  - dnl this location ist chosen if boost libraries are installed with the --layout=system option
  + dnl this location is chosen if boost libraries are installed with the --layout=system option
  dnl or if you install boost with RPM
  AS_IF([test "x$_AX_BOOST_BASE_boost_path" != "x"],[
  AC_MSG_CHECKING([for boostlib >= $1 ($WANT_BOOST_VERSION) includes in "$_AX_BOOST_BASE_boost_path/include"])
  