[gnome-initial-setup/wjt/vendor-conf-path-option] ci: Pass -Dvendor-conf-file in one build configuration

[Will Thompson <wjt src gnome org>]

commit 86f2ffd4d8ce9b9e328db46586c537b7eaa1fff5
Author: Will Thompson <wjt endlessm com>
Date:   Tue Jun 16 16:56:49 2020 +0100

    ci: Pass -Dvendor-conf-file in one build configuration
    
    This will verify that the project builds correctly when this option is
    set.

 .gitlab-ci.yml | 4 ++++
 1 file changed, 4 insertions(+)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 835a929b..b77ce5e7 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -58,7 +58,9 @@ before_script:
     # answer to sharing that code (#68), make those warnings non-fatal.
     - meson -Dsystemd=${EXPLICIT_FEATURES}
       --auto-features ${AUTO_FEATURES}
+      ${OPTIONS}
       -Dwerror=true -Dc_args=-Wno-error=deprecated-declarations
+      ${EXTRA_PARAMETERS}
       _build .
     - cd _build
     - ninja -v
@@ -76,9 +78,11 @@ build-minimal:
   variables:
     EXPLICIT_FEATURES: 'false'
     AUTO_FEATURES: 'disabled'
+    OPTIONS: ''
 
 build-maximal:
   <<: *job_definition
   variables:
     EXPLICIT_FEATURES: 'true'
     AUTO_FEATURES: 'enabled'
+    OPTIONS: '-Dvendor-conf-file=/var/lib/weird-vendor-specific-path.ini'