Allow to override the capturing group for the version

Currently the version pattern, if there is a match, returns the first capturing group.

I would be nice to add a parameter to the function, that defines the expecting capturing group, with a default value of 1 so this does not break any existing code.

This is a very simple improvement but it avoid to define a custom callback for a so little change and avoid duplicate code.

Example of REGEX: /("?)version\1:\s*("?)([0-9\.]+)\2\s*,/

This REGEX use backreferences, that need to define some extra capturing groups.

With the current function, we get a double quote as version number.
With a improved function, we could specify the value 3 as capturing group and get the correct version number.