clear the regular expression cache when done with make_regexps

src/gajim.py

@@ -1111,6 +1111,8 @@ class Interface:
 		# at least one character in 3 parts (before @, after @, after .)
 		self.sth_at_sth_dot_sth_re = sre.compile(r'\S+@\S+\.\S*[^\s)?]')
 		
+		sre.purge() # clear the regular expression cache
+
 	def on_emoticon_sort(self, emot1, emot2):
 		len1 = len(emot1)
 		len2 = len(emot2)