Update pacman_mirrors.py

"-m, --method METHOD" instead "-m, --method {rank,random}" and "P, --proto, --protocols PROTO [PROTO ...]" instead "-P, --proto, --protocols {all,http,https,ftp,ftps} [{all,http,https,ftp,ftps} ...]" isn't a good idea I suppose.

for translation
regenerated pot-file
updated test

rebuild mo-files

pep fix to setup.py

fix: root is not required to read current branch

refactor to use up-to-date mirrors on users branch