fixed Kernel::stripComments() normalizing new-lines

This makes normalizing new-lines less error-prone
when a string contains multiple new line-lines
bug #10351 [HttpKernel] fix stripComments() normalizing new-lines (sstok)

This PR was merged into the 2.3 branch.

Discussion
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[HttpKernel] fix stripComments() normalizing new-lines

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #10227
| License       | MIT
| Doc PR        |

This makes normalizing new-lines less error-prone
when a string contains multiple new line-lines

Commits
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63032c7 fixed Kernel::stripComments() normalizing new-lines