[2/4] HR support: Add logic to fetch reference source code and build it

Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
diff --git a/configure.ac b/configure.ac
index eb2c332..a8244c2 100644
--- a/configure.ac
+++ b/configure.ac
@@ -27,6 +27,7 @@
 	[enable_gsmhr=0], [enable_gsmhr=1])
 AM_CONDITIONAL(ENABLE_GSMHR, test "x$enable_gsmhr" = "x1")
 if test "x$enable_gsmhr" = "x1"; then
+	AM_PATH_PYTHON([2.4])
 	AC_DEFINE(HAVE_LIBGSMHR, 1, [Define to 1 if libgsmhr is available])
 fi