add updates and security repos as package source sources

.gitlab-ci.yml

@@ -15,8 +15,11 @@ variables:
   QUILT_PATCHES: "debian/patches"
 
 before_script:
-  # yamllint disable-line rule:line-length
+  # yamllint disable rule:line-length
   - echo "deb-src http://ftp.halifax.rwth-aachen.de/debian/ buster main" > /etc/apt/sources.list.d/buster_src.list
+  - echo "deb-src http://ftp.halifax.rwth-aachen.de/debian/ buster-updates main" >> /etc/apt/sources.list.d/buster_src.list
+  - echo "deb-src http://security.debian.org/ buster/updates main" >> /etc/apt/sources.list.d/buster_src.list
+  # yamllint enable rule:line-length
   - apt-get update
   - apt-get install -y apt-utils