Suppress error if a monthly log file does not exist

irclog.py

@@ -889,9 +889,12 @@ class WebServer:
 
 	def _file_iter_with_path(self, fn, path):
 		# Open fn, iterate over its lines yielding (path, line) tuples
-		with open(fn, 'r') as fp:
-			for line in fp:
-				yield (path, line)
+		try:
+			with open(fn, 'r') as fp:
+				for line in fp:
+					yield (path, line)
+		except FileNotFoundError:
+			pass
 
 	def _stdout_with_path(self, stdout):
 		# Process grep output with --with-filenames, --null, and --line-number into (path, line) tuples.