Increase disk limit per job

In order to move bazel caches around, increase the disk usage limit
on the executor to 1G.

Change-Id: Idc50b9cf94d7530b80443b8e519ed3b7073d535e
diff --git a/zuul/zuul.conf b/zuul/zuul.conf
index e770e93..f7c0eb3 100644
--- a/zuul/zuul.conf
+++ b/zuul/zuul.conf
@@ -23,7 +23,7 @@
 [executor]
 private_key_file=/var/lib/zuul/ssh/nodepool_id_rsa
 trusted_ro_paths=/authdaemon/token
-disk_limit_per_job=500
+disk_limit_per_job=1000
 
 [connection "sql"]
 name=sql