Correct a little spelling mistake
Revert "[4.2] Allows Arr::only To Handle Dotted Keys"
Merge pull request #6717 from laravel/revert-5746-4.2-array-only-dotted

Revert "[4.2] Allows Arr::only To Handle Dotted Keys"
Merge pull request #6708 from RomainLanz/4.2

[4.2] Correct A Little Spelling Mistake
fix conflicts.