[gupnp] ci: Docs is a feature, not a bool

[Jens Georg <jensgeorg src gnome org>]

commit 74dcdcaa01c1689268e7ae98d3c0e231c10e6db0
Author: Jens Georg <mail jensge org>
Date:   Sun Apr 24 21:46:38 2022 +0200

    ci: Docs is a feature, not a bool

 .gitlab-ci.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index eaec5ed..6ea08fb 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -53,7 +53,7 @@ check-merge-request:
   stage: build
   script:
       - git clone --depth=1 https://gitlab.gnome.org/GNOME/libsoup.git && pushd libsoup
-      - meson _build --prefix=/usr -Dtls_check=false -Ddocs=false
+      - meson _build --prefix=/usr -Dtls_check=false -Ddocs=disabled
       - ninja -C _build install
       - popd  
       - meson . build --prefix=/usr -Db_coverage=true