File make_gtk_doc_optional.patch of Package libappindicator

--- a/configure.ac	2019-09-18 20:01:29.244433451 +0200
+++ b/configure.ac	2019-09-18 20:59:47.284282932 +0200
@@ -33,8 +33,12 @@
 # GTK Doc
 ###########################
 
+# check for gtk-doc
+m4_ifdef([GTK_DOC_CHECK], [
 GTK_DOC_CHECK([1.14],[--flavour no-tmpl])
-
+],[
+AM_CONDITIONAL([ENABLE_GTK_DOC], false)
+])
 
 ###########################
 # Dependencies