Improve spelling: Rebase from -> Rebase onto

app/views/projects/merge_requests/widget/open/_ff_accept.html.haml

@@ -19,7 +19,7 @@
         - else
           .accept-action
             = f.button class: "btn btn-reopen rebase-mr" do
-              Rebase from #{@merge_request.target_branch}
+              Rebase onto #{@merge_request.target_branch}
       .accept-control
         Fast-forward merge is not possible. Branch must be rebased first
 
@@ -32,4 +32,4 @@
   $('.rebase-mr-form').on 'ajax:before', ->
     btn = $('.rebase-mr')
     btn.disable()
-    btn.html("<i class='fa fa-spinner fa-spin'></i> Rebase in progress. It could take some time")
+    btn.html("<i class='fa fa-spinner fa-spin'></i> Rebase in progress. It could take some time")
\ No newline at end of file