Cancel the reconnect timer when appropriate.

Signed-off-by: Moritz Ulrich <moritz@tarn-vedra.de>
weechat-button: Don't create overlapping buttons

This prevents #baz in http://foo.com?foo=bar#baz being a clickable
channel link

Signed-off-by: Moritz Ulrich <moritz@tarn-vedra.de>