Update JGit version to 42917767f

In this change in JGit: [1] dependency to commons-codec has been added.
To built JGit in tree in gitiles we also need to add this dependency.

[1] https://gerrit.googlesource.com/jgit/+/49beb5ae519e429d8868b8afe24007ae2d17003a
Change-Id: I4d3655a7643ec9104f33617859ff017efb5f0e20

lib/BUILD

diff --git a/lib/BUILD b/lib/BUILD
index 4fec826..f6ba7ec 100644
--- a/lib/BUILD
+++ b/lib/BUILD
@@ -10,6 +10,7 @@
 ) for n in [
     "autolink",
     "commonmark",
+    "commons-codec",
     "commons-lang3",
     "commons-text",
     "cm-autolink",
@@ -29,9 +30,9 @@
 ]]
 
 java_library(
-  name = "prettify",
-  visibility = ["//visibility:public"],
-  exports = ["@java-prettify"],
+    name = "prettify",
+    visibility = ["//visibility:public"],
+    exports = ["@java-prettify"],
 )
 
 java_library(