get rid of hack to support label attribute for 1.7.0

Summary:
as titled, an ugly hack to support LABEL attribute for 1.7.0 which didn't exist.

getting rid of it now since oss support upgraded to 1.7.1

Differential Revision: D27536730

fbshipit-source-id: 58653e71cbf20a1cda0b7414f66b5f0014d89b84

build/fbcode_builder/manifests/libsai

@@ -2,12 +2,12 @@
 name = libsai
 
 [download]
-url = https://github.com/opencomputeproject/SAI/archive/v1.7.0.tar.gz
-sha256 = ff0a07d27e1e8b762c087b9b430dd1f219a3159e155132e2f2ea39e619d8ad5f
+url = https://github.com/opencomputeproject/SAI/archive/v1.7.1.tar.gz
+sha256 = e18eb1a2a6e5dd286d97e13569d8b78cc1f8229030beed0db4775b9a50ab6a83
 
 [build]
 builder = nop
-subdir = SAI-1.7.0
+subdir = SAI-1.7.1
 
 [install.files]
 inc = include