package/python-magic-wormhole: bump to version 0.19.2
For change log since version 0.17.0, see:
https://github.com/magic-wormhole/magic-wormhole/blob/0.19.2/NEWS.md
Note that, since v0.18.0, magic-wormhole is using python-qrcode. This
commit reflects that change by adding this new runtime dependency in
Config.in.
Signed-off-by: Julien Olivain <ju.o@free.fr>