Update dependencies from Gerrit core stable-3.4

Only update dependencies found in Core's WORKSPACE file [1] and skip ones
from tools/nongoogle.bzl [2].

Also updates javax.servlet-api dependency to 3.1 for compatibility with
the Jetty version bump.

[1] https://gerrit.googlesource.com/gerrit/+/refs/heads/stable-3.4/WORKSPACE
[2] https://gerrit.googlesource.com/gerrit/+/refs/heads/stable-3.4/tools/nongoogle.bzl

Change-Id: Ic2aa2577b39cc37e3b5d5f0364a37f67d1f137dd

lib/jetty/BUILD

diff --git a/lib/jetty/BUILD b/lib/jetty/BUILD
index 5517d65..4f58b3d 100644
--- a/lib/jetty/BUILD
+++ b/lib/jetty/BUILD
@@ -8,7 +8,7 @@
     name = "servlet",
     exports = [
         ":security",
-        "//lib:servlet-api_3_0",  # Different from the rest of gitiles-server.
+        "//lib:servlet-api_3_1",  # Different from the rest of gitiles-server.
         "@servlet//jar",
     ],
 )