Fix build without glib, again

src/Makefile.am

@@ -50,14 +50,14 @@ HBHEADERS += \
 endif
 
 libharfbuzz_la_SOURCES = $(HBSOURCES) $(HBHEADERS)
-libharfbuzz_la_CPPFLAGS = -DHAVE_GLIB $(GLIB_CFLAGS)
+libharfbuzz_la_CPPFLAGS = $(GLIB_CFLAGS)
 libharfbuzz_la_LIBADD = $(GLIB_LIBS)
 pkginclude_HEADERS = $(HBHEADERS)
 
 noinst_PROGRAMS = main
 
 main_SOURCES = main.cc
-main_CPPFLAGS = -DHAVE_GLIB $(GLIB_CFLAGS)
+main_CPPFLAGS = $(GLIB_CFLAGS)
 main_LDADD = libharfbuzz.la $(GLIB_LIBS)
 
 -include $(top_srcdir)/git.mk