Launcher: only render Help button when help documents actually exist

Change-Id: If288e8bf40425d421a43ee4dd0e84136e44ddf9a
diff --git a/core/installer/welcome/launcher-tmpl/launcher.html b/core/installer/welcome/launcher-tmpl/launcher.html
index 30971a6..9b243fd 100644
--- a/core/installer/welcome/launcher-tmpl/launcher.html
+++ b/core/installer/welcome/launcher-tmpl/launcher.html
@@ -27,7 +27,9 @@
                     </div>
                     <div class="tooltip">
                         <p>{{ .Name }}</p>
+						{{ if .Help }}
                         <button class="help-button" id="help-button-{{ CleanAppName .Name }}">Help</button>
+						{{ end }}
                     </div>
                 </div>
                 <dialog class="app-help-modal" id="modal-{{ CleanAppName .Name }}" close>