logilab-common #3691182 generate_config mess up multi-line strings [validation pending]

The ini format allows multiline strings, for example:

... code-block:

value=
    line1
    line2
    line3

If such a value is written in the configuration, it is properly parsed, but changed into the following by generate_config:

... code-block:

value=line1
line2
line3

Which will not be parsed correctly especially when the lines contain the '=' character.