Suppose the wildcard patterns follows:

- *.nghttp2.org/foo
- *.img.nghttp2.org/bar

Previously, s.img.nghttp2.org/foo does not match anything.  Now it
matches first pattern.

Instead of using bool flag, just stop prepare watcher.

This is a legacy of SPDY era where it can disable flow control.

This is the unit of sharing configurations to change