Issue #3046 is triggered by html/template changes in go1.9.
See https://tip.golang.org/pkg/html/template. Quote:
// To ease migration to Go 1.9 and beyond, "html" and "urlquery" will
// continue to be allowed as the last command in a pipeline. However, if the
// pipeline occurs in an unquoted attribute value context, "html" is
// disallowed. Avoid using "html" and "urlquery" entirely in new templates.
The commit also includes a trivial whitespace fix.
I got feedback from different sources about rules and targets being
too heavy in the status tab if their are lots of them.
This change also allows for more fine-granular locking.
