MINOR: haproxy: export run_poll_loop

This will help refine debug traces.
diff --git a/include/types/global.h b/include/types/global.h
index 0ba3b0f..ad15783 100644
--- a/include/types/global.h
+++ b/include/types/global.h
@@ -276,6 +276,7 @@
 
 int main(int argc, char **argv);
 void deinit(void);
+void run_poll_loop(void);
 void hap_register_build_opts(const char *str, int must_free);
 void hap_register_post_check(int (*fct)());
 void hap_register_post_proxy_check(int (*fct)(struct proxy *));