filter expert: treat filter_regex false as False

if the parameter
filter_regex: false
was set, the bot treated this as true
with this patch, false is treated as false

CHANGELOG.md

@@ -34,6 +34,8 @@
 #### Experts
 - `intelmq.bots.experts.sieve.expert`:
   - For `:contains`, `=~` and `!~`, convert the value to string before matching avoiding an exception. If the value is a dict, convert the value to JSON (PR#2500 by Sebastian Wagner).
+- `intelmq.bots.experts.filter.expert`:
+  - Treat value `false` for parameter `filter_regex` as false (PR#2499 by Sebastian Wagner).
 
 #### Outputs
 - `intelmq.bots.outputs.misp.output_feed`: Handle failures if saved current event wasn't saved or is incorrect (PR by Kamil Mankowski).

intelmq/bots/experts/filter/expert.py

@@ -64,7 +64,7 @@ def init(self):
             self.filter = False
 
         self.regex = False
-        if self.filter_regex is not None:
+        if self.filter_regex and self.filter_regex:
             self.regex = re.compile(self.filter_value)
 
         self.time_filter = self.not_after is not None or self.not_before is not None