More accurate error message at IsDivisible

[Rudxain]

know more

Describe your change:

• Add an algorithm?
• Fix a bug or typo in an existing algorithm?
• Documentation change?

This PR edits the error message in that file (Maths/IsDivisible.js) to be more accurate to its context. Because Infinity and NaN aren't valid Real numbers.

Checklist:

• I have read CONTRIBUTING.md.
• This pull request is all my own work -- I have not plagiarized.
• I know that pull requests will not be merged if they fail the automated tests.
• This PR only changes one algorithm file. To ease review, please open separate PRs for separate algorithms.
• All new JavaScript files are placed inside an existing directory.
• All filenames should use the UpperCamelCase (PascalCase) style. There should be no spaces in filenames.
  Example:UserProfile.js is allowed but userprofile.js,Userprofile.js,user-Profile.js,userProfile.js are not
• All new algorithms have a URL in its comments that points to Wikipedia or other similar explanation.
• If this pull request resolves one or more open issues then the commit message contains Fixes: #{$ISSUE_NO}.

[appgurueu]

(consider lowercasing the r from real)

[Rudxain]

(consider lowercasing the r from real)

Why? I thought it was a good idea to make it uppercase to distinguish between "real" (reality) and "Real" (the set of all non-complex rational and irrational numbers). But, for consistency, it may also be a good idea to lowercase it

[appgurueu]

Why? I thought it was a good idea to make it uppercase to distinguish between "real" (reality) and "Real" (the set of all non-complex rational and irrational numbers). But, for consistency, it may also be a good idea to lowercase it

"real number" already is an unambiguous term and thus fine - no need to bend the rules of capitalization to emphasize the "real" property.

[Rudxain]

Ok then I'll change it now