Improve S109 message

[pavel-mikula-sonarsource]

The current message is this

Assign this magic number '2' to a well-named (variable|constant), and use the (variable|constant) instead.

That's literal copy/paste from rspec
https://github.com/SonarSource/rspec/blob/master/rules/S109/message.adoc

but this rspec notation was supposed to be implemented as one of those two variants. Users should not see it.
It should have been

Assign this magic number '2' to a well-named constant, and use the constant instead.

or

Assign this magic number '2' to a well-named variable, and use the variable instead.

or we can go around like this

Assign this magic number '2' to a well-named variable or constant, and use that instead.