Upgrade JGit to 4.7.7.201812240805-r

To match the version used in Gerrit 2.14.18.

Change-Id: I0384305a9c7b895b21c1e0a9d35885dee038253f
diff --git a/external_plugin_deps.bzl b/external_plugin_deps.bzl
index 41731ab..5da0bd1 100644
--- a/external_plugin_deps.bzl
+++ b/external_plugin_deps.bzl
@@ -111,8 +111,8 @@
     maven_jar(
         name = "jgit",
         artifact =
-            "org.eclipse.jgit:org.eclipse.jgit:4.7.2.201807261330-r",
-        sha1 = "6c08ef848fa5f7d5d49776fa25ec24d738ee457d",
+            "org.eclipse.jgit:org.eclipse.jgit:4.7.7.201812240805-r",
+        sha1 = "d2358e838084d2482d51b51b70fd34a356495925",
     )
 
     maven_jar(