irc: toggle error replies (#1071)

Adds config option to toggle Sopel replying directly to the error source.

sopel/config/core_section.py

@@ -178,6 +178,9 @@ def homedir(self):
     It is a regular expression (so the default, ``\.``, means commands start
     with a period), though using capturing groups will create problems."""
 
+    reply_errors = ValidatedAttribute('reply_errors', bool, default=True)
+    """Whether to message the sender of a message that triggered an error with the exception."""
+
     throttle_join = ValidatedAttribute('throttle_join', int)
     """Slow down the initial join of channels to prevent getting kicked.
 

sopel/irc.py

@@ -368,10 +368,10 @@ def error(self, trigger=None):
                 stderr("Could not save full traceback!")
                 LOGGER.error("Could not save traceback from %s to file: %s", trigger.sender, str(e))
 
-            if trigger and trigger.sender is not None:
+            if trigger and self.config.core.reply_errors and trigger.sender is not None:
                 self.msg(trigger.sender, signature)
         except Exception as e:
-            if trigger and trigger.sender is not None:
+            if trigger and self.config.core.reply_errors and trigger.sender is not None:
                 self.msg(trigger.sender, "Got an error.")
                 LOGGER.error("Exception from %s: %s", trigger.sender, str(e))