fix gitlab link for non-content pages

layouts/_default/baseof.html

@@ -102,7 +102,7 @@
       <div class="container">
         <div class="editPage">
           <i class="fa fa-pencil"></i>
-          <a href="{{ .Site.Params.gitEditBaseUrl }}{{ .File.Path }}" title="{{ i18n "editPage" }}">{{ i18n "editPage" }}</a>
+          <a href="{{ .Site.Params.gitEditBaseUrl }}{{ with .File }}{{ .Path }}{{ end }}" title="{{ i18n "editPage" }}">{{ i18n "editPage" }}</a>
         </div>
         <div class="center">
           <a href="/impressum">{{ i18n "imprint" }}</a>