Fix warning on nil comparison

[ekohl]

This uses the more efficient /regex/.match?(value) syntax that also doesn't raise any warning if id is nil.

[ekohl]

@chris1984 are you sure the change didn't cause those test failures?

[chris1984]

Blah, I did not mean to hit merge, was adding that I would start testing it with the quick responses and my browser crashed. Let me revert and test it, if it's not related we can remerge. Acked it based on the code looking fine at a first glance.

[nofaralfasi]

I believe this change is causing errors in Foreman's test suite.

[ekohl]

I believe this change is causing errors in Foreman's test suite.

Can you elaborate?

[nofaralfasi]

This change introduces the following error, when running the tests on foreman/test/models/compute_resources/vmware_test.rb:

Error:
Foreman::Model::VmwareTest::#clone_vm#test_0004_passes customspec when user_data is a valid yaml hash:
TypeError: no implicit conversion of Integer into String
    app/models/compute_resources/foreman/model/vmware.rb:605:in `clone_vm'
    test/models/compute_resources/vmware_test.rb:715:in `block (2 levels) in <class:VmwareTest>'

Error:
Foreman::Model::VmwareTest::#clone_vm#test_0003_ignores customspec when user_data is nil:
TypeError: no implicit conversion of Integer into String
    app/models/compute_resources/foreman/model/vmware.rb:605:in `clone_vm'
    test/models/compute_resources/vmware_test.rb:706:in `block (2 levels) in <class:VmwareTest>'

We are encountering this error when client.servers.get is called on an Integer (here).

[ekohl]

That could be related, but previously that also generated a warning I think. A better check is probably is_a?(String) && ....

[ekohl]

Expanding on that: it was a bug before anyway on modern Ruby anyway:

$ pry
[1] pry(main)> 5 =~ /a/
NoMethodError: undefined method `=~' for an instance of Integer (NoMethodError)
from (pry):1:in `__pry__'

IIRC Ruby 3.0 already displayed a deprecation warning and this was trying to address it. I'll submit a PR.

[ekohl]

#310