Fix of `get_discussions_by_author_before_date` pattern

hivemind/tavern/tags_api_patterns/get_discussions_by_author_before_date/not_full_permlink.pat.json

-[]
+{
+  "code": -32602,
+  "data": "Post dragonho/suntory-time-weekend does not exist",
+  "message": "Invalid parameters"
+}

hivemind/tavern/tags_api_patterns/get_discussions_by_author_before_date/not_full_permlink.tavern.yaml

@@ -3,6 +3,7 @@
 
   marks:
     - patterntest
+    - negative
 
 
   includes:
@@ -26,4 +27,5 @@
           function: validate_response:compare_response_with_pattern
           extra_kwargs:
             method: "not_full_permlink"
-            directory: "tags_api_patterns/get_discussions_by_author_before_date"
+            directory: "tags_api_patterns/get_discussions_by_author_before_date"
\ No newline at end of file
+            error_response: true
\ No newline at end of file