Upgrade JGit to 4.9.2.201712150930-r.15-g5fe8e31d4

This is a snapshot built from the head of JGit's stable-4.9 branch and
includes the following commits since the currently used version:

  5fe8e31d4 Ensure DirectoryStream is closed promptly
  d13918310 Retry stale file handles on .git/config file
  185e53bce Fix ssh host name handling for Jsch
  891103609 Jsch overrides the port in the URI with the one in ~/.ssh/config
  3d6455331 Minor fixes in three error messages
  bea3b4667 Revert handling of ssh IdentityFile to pre-4.9 behavior
  279eaf069 Strings#convertGlob: fix escaping of patterns like [\[].

The one we're interested in is:

  5fe8e31d4 Ensure DirectoryStream is closed promptly

which fixes a leak of file handles when running GC.

Bug: Issue 8915
Change-Id: I9571d9df7ee0df2bae788ef10442e2c9e28797e9

lib/jgit/jgit.bzl

@@ -1,6 +1,6 @@
 load("//tools/bzl:maven_jar.bzl", "GERRIT", "MAVEN_LOCAL", "MAVEN_CENTRAL", "maven_jar")
 
-_JGIT_VERS = "4.9.2.201712150930-r.4-g085d1f959"
+_JGIT_VERS = "4.9.2.201712150930-r.15-g5fe8e31d4"
 
 _DOC_VERS = "4.9.2.201712150930-r"  # Set to _JGIT_VERS unless using a snapshot
 
@@ -26,28 +26,28 @@ def jgit_maven_repos():
         name = "jgit_lib",
         artifact = "org.eclipse.jgit:org.eclipse.jgit:" + _JGIT_VERS,
         repository = _JGIT_REPO,
-        sha1 = "1b9090699d03f57b2f3e682dd4a87ddf6bf460ac",
-        src_sha1 = "46ed37a4a385e7dc3fb65ccf165e5f854698186f",
+        sha1 = "dd93e272fb38c4a0e2b9e1cc39424e1e8d542352",
+        src_sha1 = "78d34eb21320b8262a1b52bd5c91e66380d0302a",
         unsign = True,
     )
     maven_jar(
         name = "jgit_servlet",
         artifact = "org.eclipse.jgit:org.eclipse.jgit.http.server:" + _JGIT_VERS,
         repository = _JGIT_REPO,
-        sha1 = "27c490cc62a6efd4d4bc10789e8e5945fd01458b",
+        sha1 = "5ef78cf1da610c643a9fd03763b4cac2889567af",
         unsign = True,
     )
     maven_jar(
         name = "jgit_archive",
         artifact = "org.eclipse.jgit:org.eclipse.jgit.archive:" + _JGIT_VERS,
         repository = _JGIT_REPO,
-        sha1 = "bff16e9ae593808fd8b77f8917fb44c73d2eb2f3",
+        sha1 = "238e20f82cb7b5ad99b60445d36f6c2c13ed8e4e",
     )
     maven_jar(
         name = "jgit_junit",
         artifact = "org.eclipse.jgit:org.eclipse.jgit.junit:" + _JGIT_VERS,
         repository = _JGIT_REPO,
-        sha1 = "87f5f48bf2efa11726e2751f316f49c8f2429ee8",
+        sha1 = "e16e9635020e8a4a62d93cd05869442690f54209",
         unsign = True,
     )