Fix issue when a URL is incorrectly parsed.

This patch fixes #269.

Indeed, while using urllib.parse.urlpase, the hostname may be a NoneType.
Therefore, the following exception has been raised by other subsystem that
try to lookup the IP of hte hostname.

    TypeError: <self.subject> should be <class 'str'>, <class 'NoneType'>
    given.

This patch fixes it by double checking if a NoneType is sent for DNS
resolution.

Contributors:
  * @T145

Author: funilrys

PyFunceble/query/requests/adapter/base.py

@@ -176,6 +176,8 @@ def resolve(self, hostname: str) -> Optional[str]:
         Resolves with the prefered method.
         """
 
-        if self.resolving_use_cache:
-            return self.resolve_with_cache(hostname)
-        return self.resolve_without_cache(hostname)
+        if hostname:
+            if self.resolving_use_cache:
+                return self.resolve_with_cache(hostname)
+            return self.resolve_without_cache(hostname)
+        return None