diff_block: fix link to file revisions

Pull requests would link to file revisions in the wrong repo. That was
obviously only visible when merging between different repos - but then it would
link to a non-existing revision.

diff_block is apparently used pull-request-style with the 'b' revision of the
diff shown first. It thus also has to point at the 'other' repo which is where
the other revision can be found.

rhodecode/templates/changeset/diff_block.html

@@ -52,7 +52,7 b''
           <div class="changeset_header">
               <div class="changeset_file">
                   ${h.safe_unicode(filenode_path)} |
-                  <a class="spantag" href="${h.url('files_home', repo_name=c.repo_name, f_path=filenode_path, revision=c.org_ref)}" title="${_('show file at latest version in this repo')}">${c.org_ref_type}@${h.short_id(c.org_ref) if c.org_ref_type=='rev' else c.org_ref}</a> -&gt;
+                  <a class="spantag" href="${h.url('files_home', repo_name=c.other_repo.repo_name, f_path=filenode_path, revision=c.org_ref)}" title="${_('show file at latest version in this repo')}">${c.org_ref_type}@${h.short_id(c.org_ref) if c.org_ref_type=='rev' else c.org_ref}</a> -&gt;
                   <a class="spantag" href="${h.url('files_home', repo_name=c.repo_name, f_path=filenode_path, revision=c.other_ref)}" title="${_('show file at initial version in this repo')}">${c.other_ref_type}@${h.short_id(c.other_ref) if c.other_ref_type=='rev' else c.other_ref}</a>
               </div>
           </div>