prevent doubly passing our CFLAGS
--- libesmtp-1.0.6.orig/crammd5/Makefile.in	2010-08-09 22:25:56.000000000 +0200
+++ libesmtp-1.0.6/crammd5/Makefile.in	2014-06-05 22:27:13.400815451 +0200
@@ -225,7 +225,7 @@ top_build_prefix = @top_build_prefix@
 top_builddir = @top_builddir@
 top_srcdir = @top_srcdir@
 INCLUDES = -I@srcdir@
-AM_CFLAGS = @CFLAGS@ @EXTRA_CFLAGS@
+AM_CFLAGS = @EXTRA_CFLAGS@
 lib_LTLIBRARIES = sasl-cram-md5.la
 sasl_cram_md5_la_SOURCES = client-crammd5.c hmacmd5.c hmacmd5.h
 sasl_cram_md5_la_LDFLAGS = -module -avoid-version @CRAMMD5_LIBS@