Fix issue with the integration of the collection.

This patch fixes #273.

Indeed, while deploying the source code related to the collection, the
integration into existing infrastructure wasn't smooth.
This patch fixes it by loading the collection later in the loading
process.

Contributors:
  * @ZeroDot1
  * @DandelionSprout

Author: funilrys

PyFunceble/config/loader.py

@@ -398,7 +398,8 @@ def start(self) -> "ConfigLoader":
         PyFunceble.storage.HTTP_CODES = Box(
             config["http_codes"],
         )
-        PyFunceble.storage.COLLECTION = Box(config["collection"])
+        if "collection" in config:
+            PyFunceble.storage.COLLECTION = Box(config["collection"])
         PyFunceble.storage.LINKS = Box(config["links"])
 
         return self