--- firefox-49.0.1.orig/old-configure.in	2016-09-05 22:12:50.000000000 +0200
+++ firefox-49.0.1/old-configure.in	2016-10-01 23:25:33.657828298 +0200
@@ -6,7 +6,6 @@ dnl file, You can obtain one at http://m
 
 dnl Process this file with autoconf to produce a configure script.
 dnl ========================================================
-AC_PREREQ(2.13)
 AC_INIT(config/config.mk)
 AC_CONFIG_AUX_DIR(${srcdir}/build/autoconf)
 AC_CANONICAL_SYSTEM