ISTWCMS-4537: Downgrade to filefield_sources ee23c9a

This is a temporary fix to make testing work again.

composer.json

@@ -58,7 +58,7 @@
         "drupal/field_group": "3.1",
         "drupal/field_validation": "1.0-beta3",
         "drupal/file_mdm": "2.1",
-        "drupal/filefield_sources": "1.0-alpha4",
+        "drupal/filefield_sources": "dev-8.x-1.x#ee23c9a",
         "drupal/geofield": "1.15",
         "drupal/geofield_map": "2.67",
         "drupal/hcaptcha": "1.1",