To prevent:
configure.ac:80: error: possibly undefined macro: AM_GCONF_SOURCE_2

diff -Naur a/configure.ac b/configure.ac
--- a/configure.ac	2017-05-09 18:21:44.000000000 +0100
+++ b/configure.ac	2019-03-10 17:14:20.222932063 +0000
@@ -77,7 +77,6 @@
 dnl GConf stuff
 dnl ***********
 AC_PATH_PROG(GCONFTOOL, gconftool-2, no)
-AM_GCONF_SOURCE_2
 
 dnl ***************
 dnl Libappindicator stuff