Docker registry - Allow replace tag based on regular expression

For now we can either enable or disable replacing already existing tags.

:latest tags are replaceable 

We use a naming convention known for Maven projects in JAVA with -SNAPSHOT postfix

Artifacts with SNAPSHOT are regularly re-built and replaced.

That would help, if we could disable replacing tags in docker registry except those matching a regular expression(s).

For now we have to enable replacing globally which brings a risk that someone might replace artifact that shouldn't be replaceable.