Merge branch 'stable-5.3' into stable-5.4

* stable-5.3:
  Revert "RefDirectory.scanRef: Re-use file existence check done in snapshot creation"

Change-Id: I52a57a17abe60e30e3d7615f8cb4d0c5e6aebd9b
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>

diff --cc org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/FileSnapshot.java
Simple merge

diff --cc org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/RefDirectory.java
Simple merge