Update jordan/icinga2 Docker tag to v2.15.0

This MR contains the following updates:

Package	Type	Update	Change
jordan/icinga2	final	minor	2.14.3 -> 2.15.0
jordan/icinga2	final	minor	2.14.0 -> 2.15.0

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group_vars/prod

@@ -136,4 +136,5 @@ oauth_global:
 
 oidc_global:
   provider_url: https://uffd.warpzone.ms
-  logout_url: https://uffd.warpzone.ms/logout
\ No newline at end of file
+  logout_url: https://uffd.warpzone.ms/logout
+  ldap_base_dn: "dc=warpzone,dc=ms"