Fixed boolean/integer BC break.

Booleans and integers were being inadvertently converted to strings when
saved in the config array. This preserves the datatype.
Merge pull request #5569 from michaelmoussa/readable-config-arrays

Fixed boolean/integer BC break in Zend\Config\Writer\PhpArray
[#5569] CS fixes

- elseif -> else if
Merge branch 'hotfix/5569' into develop

Close #5569