Upgrade JGit to 4.9.8.201812241815-r

This aligns with the version used in core Gerrit since 2.15.8.

Change-Id: Ia5b11a28c75085f71e2e6541bbe2ca7482472da2
diff --git a/external_plugin_deps.bzl b/external_plugin_deps.bzl
index 9980a5a..aff59ef 100644
--- a/external_plugin_deps.bzl
+++ b/external_plugin_deps.bzl
@@ -1,13 +1,13 @@
 load("//tools/bzl:maven_jar.bzl", "GERRIT", "MAVEN_CENTRAL", "MAVEN_LOCAL", "maven_jar")
 
-JGIT_VERSION = "4.9.7.201810191756-r"
+JGIT_VERSION = "4.9.8.201812241815-r"
 REPO = MAVEN_CENTRAL
 
 def external_plugin_deps():
     maven_jar(
         name = "jgit-http-apache",
         artifact = "org.eclipse.jgit:org.eclipse.jgit.http.apache:" + JGIT_VERSION,
-        sha1 = "46b6d5102e0313fd88a681315f3cfceab631262c",
+        sha1 = "a33c9029a6ed9b0b476d0763da38d9b4ba3a0a7a",
         repository = REPO,
         unsign = True,
         exclude = [
@@ -19,7 +19,7 @@
     maven_jar(
         name = "jgit-lfs",
         artifact = "org.eclipse.jgit:org.eclipse.jgit.lfs:" + JGIT_VERSION,
-        sha1 = "1b78bf52e9aff4dc8142cecbc957129b9c7a2570",
+        sha1 = "081d5d72d927fa5897ae0bbba72fa7522d502130",
         repository = REPO,
         unsign = True,
         exclude = [
@@ -31,7 +31,7 @@
     maven_jar(
         name = "jgit-lfs-server",
         artifact = "org.eclipse.jgit:org.eclipse.jgit.lfs.server:" + JGIT_VERSION,
-        sha1 = "56fa097f1e3550d2a7ab012cc10e28653806099b",
+        sha1 = "d12cdeb61eff7f7ce43de403fadc8a378f7d4726",
         repository = REPO,
         unsign = True,
         exclude = [