ci: Switch to centos/8 image

.gitlab-ci.yml

@@ -6,7 +6,7 @@ stages:
 variables:
   DOCKER_IMAGE_BASE: registry.icinga.com/build-docker
   ICINGA_BUILD_TYPE: snapshot
-  #ICINGA_BUILD_RELEASE_TYPE: 
+  #ICINGA_BUILD_RELEASE_TYPE:
   #ICINGA_BUILD_TYPE:
   #ICINGA_BUILD_UPSTREAM_BRANCH:
 
@@ -51,22 +51,22 @@ variables:
 ###################################
 # EPEL
 ###################################
-build/rhel/8:
+build/centos/8:
   <<: *build
   variables:
-    DOCKER_IMAGE: rhel/8
+    DOCKER_IMAGE: centos/8
 
-test/rhel/8:
+test/centos/8:
   <<: *test
   variables:
-    DOCKER_IMAGE: rhel/8
+    DOCKER_IMAGE: centos/8
   dependencies:
-    - build/rhel/8
+    - build/centos/8
 
 upload/epel/8:
   <<: *upload
   dependencies:
-    - build/rhel/8
+    - build/centos/8
 
 build/centos/7:
   <<: *build