Merge pull request #466 from CybercentreCanada/Yara_prescript-fix

Yara_prescript fix[dev]

cape/cape_main.py

@@ -399,6 +399,8 @@ def execute(self, request: ServiceRequest) -> None:
 
     def _load_rules(self):
         # Generate root directory for yara rules.
+        if self.rules_directory is None:
+            return
         yara_root = os.path.join(self.rules_directory, "cape")
         errors = {}