Bump guice-multibindings to final 4.0 release

Update to the same Guice version, used in Gerrit core.

Change-Id: I542f695d8fa04afb726b2d7549f22c2692ee9ff2
diff --git a/BUCK b/BUCK
index 1b21bf4..64dacdf 100644
--- a/BUCK
+++ b/BUCK
@@ -97,8 +97,8 @@
 # guice-multibindings must match Guice version used in Gerrit
 maven_jar(
   name = 'guice-multibindings',
-  id = 'com.google.inject.extensions:guice-multibindings:4.0-beta5',
-  sha1 = 'f432356db0a167127ffe4a7921238d7205b12682',
+  id = 'com.google.inject.extensions:guice-multibindings:4.0',
+  sha1 = 'f4509545b4470bbcc865aa500ad6fef2e97d28bf',
   license = 'Apache2.0',
   exclude_java_sources = True,
   exclude = [