Remove duplicate patch file iproute2-headers.diff

OBS-URL: https://build.opensuse.org/package/show/security:netfilter/iproute2?expand=0&rev=66

iproute2-headers.diff

@@ -1,16 +0,0 @@
----
- ip/ipnetns.c |    1 +
- 1 file changed, 1 insertion(+)
-
-Index: iproute2-3.8.0/ip/ipnetns.c
-===================================================================
---- iproute2-3.8.0.orig/ip/ipnetns.c
-+++ iproute2-3.8.0/ip/ipnetns.c
-@@ -14,6 +14,7 @@
- #include <errno.h>
- #include <unistd.h>
- #include <ctype.h>
-+#include <linux/fs.h>
- 
- #include "utils.h"
- #include "ip_common.h"