[gssdp] build: Add missing ''

[Jens Georg <jensgeorg src gnome org>]

commit 9e08fa75bd75fcfa3b021191b2603a7c756cec3b
Author: Jens Georg <mail jensge org>
Date:   Sat Aug 14 10:12:47 2021 +0200

    build: Add missing ''

 tools/meson.build | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/tools/meson.build b/tools/meson.build
index aae3255..40eb8e3 100644
--- a/tools/meson.build
+++ b/tools/meson.build
@@ -1,7 +1,7 @@
 resource = gnome.compile_resources(
     'org.gupnp.GSSDP.DeviceSniffer',
     'gssdp-device-sniffer.gresource.xml',
-    source_dir: [meson.current_source_dir(), meson.current_source_dir() / .. / 'doc']
+    source_dir: [meson.current_source_dir(), meson.current_source_dir() / '..' / 'doc']
 )
 
 sniffer = executable(