https://www.php.net/strpos has the signature
`strpos ( string $haystack , mixed $needle [, int $offset = 0 ] ) : int`
(The needle is usually the constant)
`strpos('/', $suggestion)` would only be `false` for `''` and `'/'`
So the existing check would just not suggest **anything** that was
already installed (from pecl, built-in, or composer).
The intent seems to be to not suggest non-vendored php packages
that were already installed. (b20cc22ebb)
Stephan Vock