[gnome-build-meta] elements/sdk/libsecret.bst: Disable building docs

[Javier Jardón Cabezas <jjardon src gnome org>]

commit 564b8a7280efbb00e2201cfb911f24dd83dc7b54
Author: Javier Jardón <jjardon gnome org>
Date:   Sun Aug 11 19:17:40 2019 +0100

    elements/sdk/libsecret.bst: Disable building docs
    
    Currently is failing with:
    ```
    Traceback (most recent call last):
              File "/usr/lib/python3.7/shutil.py", line 566, in move
                os.rename(src, real_dst)
            FileNotFoundError: [Errno 2] No such file or directory: 
'/buildstream/gnome/sdk/libsecret.bst/_builddir/docs/reference/libsecret/html/libsecret.devhelp2' -> 
'/buildstream/gnome/sdk/libsecret.bst/_builddir/docs/reference/libsecret/html/libsecret-1.devhelp2'
    ```

 elements/sdk/libsecret.bst | 4 ++++
 1 file changed, 4 insertions(+)
---
diff --git a/elements/sdk/libsecret.bst b/elements/sdk/libsecret.bst
index 5d4aeb92..a42af801 100644
--- a/elements/sdk/libsecret.bst
+++ b/elements/sdk/libsecret.bst
@@ -20,3 +20,7 @@ depends:
   type: build
 - filename: bootstrap-import.bst
   junction: freedesktop-sdk.bst
+
+variables:
+  meson-local: >-
+    -Dgtk_doc=false