[master] d5d5637 Redundant assert

[Dridi Boukelmoune]

commit d5d5637d2fa3b0be05464c579893bc7806831081
Author: Dridi Boukelmoune <dridi.boukelmoune at gmail.com>
Date:   Wed Feb 1 13:22:55 2017 +0100

    Redundant assert
    
    It actually fails to build with recent enough GCC or Clang.

diff --git a/lib/libvmod_directors/vdir.c b/lib/libvmod_directors/vdir.c
index 28f28f9..1581346 100644
--- a/lib/libvmod_directors/vdir.c
+++ b/lib/libvmod_directors/vdir.c
@@ -157,7 +157,6 @@ vdir_remove_backend(struct vdir *vd, VCL_BACKEND be, unsigned *cur)
 	vd->n_backend--;
 
 	if (cur) {
-		assert(*cur >= 0);
 		assert(*cur <= vd->n_backend);
 		if (u < *cur)
 			(*cur)--;