fix(acf-composer): Fix relative path when using ACF Composer inside o…

…f a plugin (Fixes #125) (#133)

src/AcfComposer.php

@@ -89,7 +89,7 @@ public function registerPath($path, $namespace = null)
 
         foreach ((new Finder())->in($paths->toArray())->files()->sortByName() as $file) {
             $relativePath = str_replace(
-                $this->app->path() . DIRECTORY_SEPARATOR,
+                Str::finish($path, DIRECTORY_SEPARATOR),
                 '',
                 $file->getPathname()
             );