Fix lightweight tags not processed correctly by GitTagPushService

When we updated gitlab_git to 10.4.1, `tag.target` changed from pointing
to the sha of the tag to the sha of the commit the tag points to. The
problem is that only annotated tags have `object_sha`s, lightweight tags
don't (it's nil), so (only) in their case we still need to use
`tag.target`.

1 files changed, 2 insertions, 2 deletions

diff --git a/lib/api/entities.rb b/lib/api/entities.rb
index feaa0c213bf..ab9d2d54f4b 100644
--- a/lib/api/entities.rb
+++ b/lib/api/entities.rb
@@ -138,7 +138,7 @@ module API
       expose :name
 
       expose :commit do |repo_branch, options|
-        options[:project].repository.commit(repo_branch.target)
+        options[:project].repository.commit(repo_branch.dereferenced_target)
       end
 
       expose :protected do |repo_branch, options|
@@ -523,7 +523,7 @@ module API
       expose :name, :message
 
       expose :commit do |repo_tag, options|
-        options[:project].repository.commit(repo_tag.target)
+        options[:project].repository.commit(repo_tag.dereferenced_target)
       end
 
       expose :release, using: Entities::Release do |repo_tag, options|