Merge branch 'stable-2.15'
* stable-2.15:
Fix access path propagation on git/ssh protocol
Fix support for setting owner of group to a single user
Set version to 2.15.5
Set version to 2.14.15
Add tests for .gitmodules validation
Remove occurrence of "is="gr-select"" in gr-create-project-dialog
Add support for "max_object_size_limit" effective value
Update JGit to 4.7.5.201810051826-r
Update JGit to 4.9.6.201810051924-r
ElasticContainer: Use Elasticsearch 6.4.2 for V6_4 tests
Upgrade elasticsearch-rest-client to 6.4.2
Upgrade jackson-core to 2.9.7
This merge partially reverts change I27fc60caf ("Upgrade jackson-core to
2.9.7") which limited the visibility of jackson-core to Elasticsearch.
Since change If4d62922f, jackson-core is exported in the plugin API
and thus its visibility cannot be restricted.
Change-Id: I69847856636ad3084d78686a02414b771cf38033
