Edit master issue template to include 2 or 3 as # of replicas

[kevzak]

On the question regarding Number of replicas to store. The dropdown on the master issue template should include 2 and 3

[willscott]

This should be done for repos where the associated json indicates that required_replicas is "2+" (2 and 3 as options) or "3+" (3 as an option)

[willscott]

We care about this primarily for future pushes