[gnome-shell] ci: Fix typo

[Marge Bot <marge-bot src gnome org>]

commit 74623479053fe10d43296fa18e6fe3733655c5e7
Author: Robert Mader <robert mader posteo de>
Date:   Tue Jan 26 21:37:43 2021 +0100

    ci: Fix typo
    
    This made us fall back to a normal debug build, not catching certain
    warnings.
    
    Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1597>

 .gitlab-ci.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 1f52c75ffb..03455eea05 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -186,7 +186,7 @@ build:
         - meson mutter mutter/build --prefix=/usr -Dtests=false
         - ninja -C mutter/build install
     script:
-        - meson . build -Dbuiltype=debugoptimized -Dman=false --werror
+        - meson . build -Dbuildtype=debugoptimized -Dman=false --werror
         - ninja -C build
         - ninja -C build install
     artifacts: