cmd/coordinator: don't delete gomote-created VMs in 45 minutes

remote.go has its own timeout tracking. Don't have the GCE VM cleanup
loop also cleaning them up based on VM's "delete-in" metadata.

The GCE VM cleanup loop will still delete unknown VMs if the
coordinator is restarted.

Change-Id: I5803f3c9431d05df8a31758820e082f60a4878fc
Reviewed-on: https://go-review.googlesource.com/12156
Reviewed-by: Austin Clements <austin@google.com>
diff --git a/cmd/coordinator/remote.go b/cmd/coordinator/remote.go
index 4dcf3e7..bf6b1f5 100644
--- a/cmd/coordinator/remote.go
+++ b/cmd/coordinator/remote.go
@@ -105,7 +105,7 @@
 
 	// rev is just a comment basically. The GCE pool uses it for
 	// naming.
-	rev := strings.TrimPrefix(user, "user-")
+	rev := user // includes "user-" prefix.
 
 	var closeNotify <-chan bool
 	if cn, ok := w.(http.CloseNotifier); ok {