Don't declare dependency on freetype in harfbuzz.pc

See comments.

src/Makefile.am

@@ -149,7 +149,12 @@ endif
 if HAVE_FREETYPE
 HBCFLAGS += $(FREETYPE_CFLAGS)
 HBLIBS   += $(FREETYPE_LIBS)
-HBDEPS   += $(FREETYPE_DEPS)
+# XXX
+# The following creates a recursive dependency on FreeType if FreeType is
+# built with HarfBuzz support enabled.  Newer pkg-config handles that just
+# fine but pkg-config 0.26 as shipped in Ubuntu 14.04 crashes.  Remove
+# in a year or two, or otherwise work around it...
+#HBDEPS   += $(FREETYPE_DEPS)
 HBSOURCES += hb-ft.cc
 HBHEADERS += hb-ft.h
 endif