Switch to JGit v5.8.1.202007141445-r

Changes:
246954e0d JGit v5.8.1.202007141445-r
f2bfaca08 Add new osgi fragments to maven-central deploy scripts
979ed737a Do not require org.assertj.core.annotations
6abe695aa Prepare 5.8.1-SNAPSHOT builds
4475a55f8 Handle Fragment-Host declaration when updating version

Change-Id: Iec8c61e6c179c6034163e46e2082b25cde2d8f22
diff --git a/modules/jgit b/modules/jgit
index 8e79d5a..246954e 160000
--- a/modules/jgit
+++ b/modules/jgit
@@ -1 +1 @@
-Subproject commit 8e79d5a290843b929f073a536a0d678fc74382ca
+Subproject commit 246954e0d66a1e38282d0786f10df8da54911628