fix a case when "ip r" command fails

our network manager script isn't the beauty of the code base.
However, this fixes a case where it would crash the reader when an
external command fails.

fixes #1279.
Merge pull request #1280 from hwhw/master

fix a case when "ip r" command fails
pull base changes: fix for <code> elements in epubs

needs https://github.com/koreader/koreader-base/pull/284
fixes #1222
Merge pull request #1293 from Frenzie/language

Reworked several strings
Merge pull request #1291 from hwhw/fix_epub_code

pull base changes: fix for <code> elements in epubs
show a popup upon making a dictionary the default dictionary
show dictionary title in info popup when setting default dictionary
Merge pull request #1294 from hwhw/fix_default_dict_set

show a popup upon making a dictionary the default dictionary