new(engine): raise warning instead of error on not-unique exceptions names

Signed-off-by: Gianmatteo Palmieri <mail@gian.im>

userspace/engine/falco_load_result.h

@@ -58,7 +58,8 @@ public:
 		LOAD_UNKNOWN_ITEM,
 		LOAD_DEPRECATED_ITEM,
 		LOAD_WARNING_EXTENSION,
-		LOAD_APPEND_NO_VALUES
+		LOAD_APPEND_NO_VALUES,
+		LOAD_EXCEPTION_NAME_NOT_UNIQUE
 	};
 
 	virtual ~load_result() = default;