BUILD: Makefile: fix linkage for Haiku.

At runtime, the haiku's loader displays `could not resolve symbol: __start_i_STG_ALLOC`
thus using linker setting fallback.

(cherry picked from commit 953771b0e30d02ed22369f9498d70bd02e9a470a)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
diff --git a/Makefile b/Makefile
index 6571dc6..158daef 100644
--- a/Makefile
+++ b/Makefile
@@ -346,7 +346,7 @@
 # Haiku
 ifeq ($(TARGET),haiku)
   TARGET_LDFLAGS = -lnetwork
-  set_target_defaults = $(call default_opts,USE_POLL USE_TPROXY)
+  set_target_defaults = $(call default_opts,USE_POLL USE_TPROXY USE_OBSOLETE_LINKER)
 endif
 
 # For linux >= 2.6.28 and glibc