fixed bug with cache entries being overwritten when 'module' was registered under 'module/index'

Let's assume there's a module registered under `"test/index"`

When you call `require( "test" )` stitch checks if it has such module in cache under `"test"` path.
If not it checks, if there's such module defined under `"test"` or `"test/index"` and tries to load it.
In this example, It finds the module under `"test/index"` so it creates cache entry for that path.

When the  same module is required again, it will be not found it cache and whole cache entry is recreated.