macOS build: exclude HOL-Proofs

--- a/Admin/jenkins/build/ci_build_makeall_seq.scala	Thu May 24 09:26:26 2018 +0000
+++ b/Admin/jenkins/build/ci_build_makeall_seq.scala	Fri May 25 21:08:00 2018 +0200
@@ -11,6 +11,6 @@
   def pre_hook(args: List[String]) = {}
   def post_hook(results: Build.Results) = {}
 
-  def selection = Sessions.Selection(all_sessions = true)
+  def selection = Sessions.Selection(all_sessions = true, exclude_sessions = List("HOL-Proofs"))
 
 }