[Rev 01] RFR: git-sync: use refspec instead of --prune-tags

[Erik Helin]

> Hi all,
> 
> please review this small patch that uses a refspec instead of `--prune-tags` for
> `GitRepository.fetchRemote`. The flag `--prune-tags` was introduced in Git 2.17
> and we want to support older Git versions, so I opted to use a refspec instead
> to achieve the same effect.
> 
> Testing:
> - Manual testing of `git sync` on Linux x64
> 
> Thanks,
> Erik

Erik Helin has updated the pull request incrementally with one additional commit since the last revision:

  Add refspec for non-tag heads as well

-------------

Changes:
  - all: https://git.openjdk.java.net/skara/pull/529/files
  - new: https://git.openjdk.java.net/skara/pull/529/files/0d9d2d27..7d032795

Webrevs:
 - full: https://webrevs.openjdk.java.net/skara/529/webrev.01
 - incr: https://webrevs.openjdk.java.net/skara/529/webrev.00-01

  Stats: 3 lines in 1 file changed: 2 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/skara/pull/529.diff
  Fetch: git fetch https://git.openjdk.java.net/skara pull/529/head:pull/529

PR: https://git.openjdk.java.net/skara/pull/529