[rygel] tracker3: Make optional for now

[Jens Georg <jensgeorg src gnome org>]

commit f4f8e96aba72791e49ad8a22769fb6df6b470e3f
Author: Jens Georg <mail jensge org>
Date:   Sun Jul 5 22:41:48 2020 +0200

    tracker3: Make optional for now

 src/plugins/tracker3/meson.build | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/src/plugins/tracker3/meson.build b/src/plugins/tracker3/meson.build
index b43359a6..a944838a 100644
--- a/src/plugins/tracker3/meson.build
+++ b/src/plugins/tracker3/meson.build
@@ -41,7 +41,7 @@ shared_module('rygel-tracker3',
               rygel_tracker_sources,
               dependencies : [
                   common_deps,
-                  dependency('tracker-sparql-3.0'),
+                  dependency('tracker-sparql-3.0', required:false, disabler: true),
                   build_config, rygel_core, rygel_server
               ],
               c_args : ['-DG_LOG_DOMAIN="RygelTracker3"'],