Bug#1126446: Update d/watch and upload to mentors.debian.net again

[Haolin Xue]

Hello,

I have fallenback d/watch to version 4, meaning that there is no lintian 'W' on 
https://mentors.debian.net/package/display-dhammapada/ any more. Now it works 
properly and reads upstream version well.

Regards,
Haolin Xue