prevent doubly passing our CFLAGS
--- libesmtp-1.0.6.orig/login/Makefile.am	2010-08-08 17:45:56.000000000 +0200
+++ libesmtp-1.0.6/login/Makefile.am	2014-06-05 22:29:47.310690185 +0200
@@ -5,7 +5,7 @@ libdir = @plugindir@
 INCLUDES = -I@srcdir@
 
 lib_LTLIBRARIES = sasl-login.la
-AM_CFLAGS = @CFLAGS@ @EXTRA_CFLAGS@
+AM_CFLAGS = @EXTRA_CFLAGS@
 
 sasl_login_la_SOURCES = client-login.c
 sasl_login_la_LDFLAGS = -module -avoid-version