fix: [stix2 import] Fixed external patterns parsing

- Avoiding brackets to be imported with the type
  and value within attributes
- Going with 55095910c

app/files/scripts/stix2/stix2misp.py

@@ -1973,6 +1973,7 @@ class ExternalStixParser(StixParser):
 
     @staticmethod
     def get_type_and_value_from_pattern(pattern):
+        pattern = pattern.strip('[]')
         try:
             pattern_type, pattern_value = pattern.split(' = \'')
         except ValueError: