increase the size of the remotehost image cache by 3x

- origingally, when the cache was size 3 that was literally enough
  images for 3 separate runs since each image was used for all aspects
  of the run

- with the change to one-tool it can take 3 images just for a basic
  run (one benchmark and two tools -- procstat and systat) so the
  image requirements have gone up

- in order to maintain a similar level of cache locality from a run
  perspective it needs to be increased, so take the basic run config
  and scale based on it

endpoints/remotehost/remotehost

@@ -43,7 +43,7 @@ fi
 # globals (also check $endpoint_base_dir/base for others!!!)
 chroot_rbind_mounts="proc dev sys lib/firmware lib/modules usr/src boot var/run"
 endpoint_name="remotehost"
-image_cache_size=3
+image_cache_size=9
 declare -A osruntime
 osruntime[default]="chroot"
 host_mounts=""