[librsvg] Fix build with newer libtool

[Behdad Esfahbod <behdad src gnome org>]

commit 23da1c0080719628aecac1cf01b1784140392240
Author: Behdad Esfahbod <behdad behdad org>
Date:   Tue Oct 28 15:47:31 2014 -0700

    Fix build with newer libtool
    
    sigh.

 Makefile.am |    2 --
 1 files changed, 0 insertions(+), 2 deletions(-)
---
diff --git a/Makefile.am b/Makefile.am
index 5c3eab6..361fecc 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -3,8 +3,6 @@ SUBDIRS = . gdk-pixbuf-loader tests tools doc
 NULL =
 BUILT_SOURCES =
 
-ACLOCAL_AMFLAGS = ${ACLOCAL_FLAGS} -I m4
-
 lib_LTLIBRARIES = librsvg- RSVG_API_MAJOR_VERSION@.la
 
 bin_PROGRAMS = rsvg-convert