[rss] Default fg/bg value shouldn't be empty string.

[oklahomer]

The code says fg and bg colours are optional as stated here, but when I send command in a form of .rss add #channel name url, it fills fg and bg with empty strings.

fg = int(match.group(4)) % 16 if match.group(4) else ''
bg = int(match.group(5)) % 16 if match.group(5) else ''

The table schema, however, allows tiny int or null, but string.

CREATE TABLE `rss_feeds` (
  `channel` text NOT NULL,
  `feed_name` text NOT NULL,
  `feed_url` text,
  `fg` tinyint(4) DEFAULT NULL,
  `bg` tinyint(4) DEFAULT NULL,
  `enabled` tinyint(1) DEFAULT '1',
  `article_title` text,
  `article_url` text,
  `published` text,
  `etag` text,
  `modified` text,
  PRIMARY KEY (`channel`(254),`feed_name`(254))
)

So the command without fg/bg, .rss add #channel name url, results in an error saying OperationalError: (1366, "Incorrect integer value: '' for column 'fg' at row 1”).

I'm working on it, now.