package/libmpdclient: bump to version 2.19

package/libmpdclient: bump to version 2.19

* fix off-by-one bug in MPD_HOST parser
* add function mpd_lookup_replay_gain_mode()
* identify messages with length over the buffer limit
* support MPD protocol 0.16
 - replay gain
* support MPD protocol 0.19
 - idle events "neighbor" and "mount"
* support MPD protocol 0.20
 - rangeid
* support MPD protocol 0.21
  - command "tagtypes all"

https://raw.githubusercontent.com/MusicPlayerDaemon/libmpdclient/v2.19/NEWS

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>