Upgrade gwtjsonrpc to version 1.9

There is no changed functionality in this release. It just syncs its
dependencies (Gson, commons-codecs) with the versions used in Gerrit.

Change-Id: I377c449f8fbce75b39dc20594111bb620f7145e0
diff --git a/lib/BUCK b/lib/BUCK
index 2d931c2..843018c 100644
--- a/lib/BUCK
+++ b/lib/BUCK
@@ -51,9 +51,9 @@
 
 maven_jar(
   name = 'gwtjsonrpc',
-  id = 'com.google.gerrit:gwtjsonrpc:1.8',
-  bin_sha1 = 'c264bf2f543cffddceada5cdf031eea06dbd44a0',
-  src_sha1 = 'cab9117b6349c04c9fdcb5b31434b3a20fd36062',
+  id = 'com.google.gerrit:gwtjsonrpc:1.9',
+  bin_sha1 = '458f55e92584fbd9ab91a89fa1c37654922a0f2b',
+  src_sha1 = 'ba539361c80a26f0d30a2f56068f6d83f44062d8',
   license = 'Apache2.0',
 )