Merge branch 'id-load-last-signature-for-blob' into 'master'

Load signature only for last commit on blob#show

See merge request gitlab-org/gitlab!18573

app/views/projects/blob/show.html.haml

 - breadcrumb_title "Repository"
 - page_title @blob.path, @ref
-- signatures_path = namespace_project_signatures_path(namespace_id: @project.namespace.full_path, project_id: @project.path, id: @last_commit)
+- signatures_path = namespace_project_signatures_path(namespace_id: @project.namespace.full_path, project_id: @project.path, id: @last_commit, limit: 1)
 
 .js-signature-container{ data: { 'signatures-path': signatures_path } }