Hide Wiki from repo header

Should only show if there is a wiki.

templates/repo/header.tmpl

@@ -59,12 +59,6 @@
 			</a>
 			{{end}}
 
-			{{if or (.Repository.UnitEnabled $.UnitTypeWiki) (.Repository.UnitEnabled $.UnitTypeExternalWiki)}}
-				<a class="{{if .PageIsWiki}}active{{end}} item" href="{{.RepoLink}}/wiki" {{if (.Repository.UnitEnabled $.UnitTypeExternalWiki)}} target="_blank" {{end}}>
-					<i class="octicon octicon-book"></i> {{.i18n.Tr "repo.wiki"}}
-				</a>
-			{{end}}
-
 			{{if and (.Repository.AnyUnitEnabled $.UnitTypePullRequests $.UnitTypeIssues $.UnitTypeReleases) (not .IsBareRepo)}}
 				<a class="{{if .PageIsActivity}}active{{end}} item" href="{{.RepoLink}}/activity">
 					<i class="octicon octicon-pulse"></i> {{.i18n.Tr "repo.activity"}}