fix iteration through list from previous commit

if last item was removed, 'it' would be set to Patterns.end()
and then for loop was incrementing 'it', bypassing conditional
for exit by that.

src/tag_editor.cpp

@@ -458,9 +458,13 @@ void TagEditor::EnterPressed()
 			}
 			else if (success)
 			{
-				for (std::list<std::string>::iterator it = Patterns.begin(); it != Patterns.end(); ++it)
+				for (std::list<std::string>::iterator it = Patterns.begin(); ; ++it)
+				{
 					if (*it == Config.pattern)
 						it = Patterns.erase(it);
+					if (it == Patterns.end())
+						break;
+				}
 				Patterns.insert(Patterns.begin(), Config.pattern);
 				quit = 1;
 			}