Use 'Forking in progress' title when appropriate

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

-- page_title "Import in progress"
+- page_title @project.forked? ? "Forking in progress" : "Import in progress"
 .save-project-loader
   .center
     %h2

changelogs/unreleased/forking-in-progress-title.yml

+---
+title: Use 'Forking in progress' title when appropriate
+merge_request: 7394
+author: Philip Karpiak