fixes issues with str_replace

Merge pull request #3 from SplashThat/bugfix/str_replace-bad-argument

fix problem with str_replace

fix some issue with str_replace and php8

Merge pull request #2 from SplashThat/bugfix/str_replace-bad-argument

allow php8 for this library

fix passing null as 3rd param to str_replace

Merge pull request #1 from SplashThat/bugfix/str_replace-bad-argument

fix passing null as 3rd argument to str_replace

compatiblity with php8

2.0.1

compatibilty with php8