Merge branch 'stable-5.1' into stable-5.2

# By Matthias Sohn (2) and Saša Živkov (1)
* stable-5.1:
  Prepare 5.1.13-SNAPSHOT builds
  JGit v5.1.12.201910011832-r
  Do not rely on ArrayIndexOutOfBoundsException to detect end of input

Change-Id: Iaae4b171eaa0081f9142489de8df94ab455d65f7
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

diff --cc org.eclipse.jgit/src/org/eclipse/jgit/lib/Config.java
Simple merge