The name `proxy-mutator` is too generic. In particular, several different linkerd extensions will have mutating webhooks which mutate the proxy sidecar, the MutatingWebhookConfiguration resource is cluster scoped, and each one needs a unique name.
We use the `jaeger-injector` name instead. This gives us a pattern to follow for future webhooks as well (e.g. `tap-injector` etc.)
Signed-off-by: Alex Leong <alex@buoyant.io>