multipart chapter naming when the "zero fill to 3 digit" in "numbers only" option is selected

[Simone Spinozzi]

if a chapter gets multiparted by the scanlators and named 5.1 ( 5.2, 5.3, etc.) and the option to "zero fill to 3 digits" is selected current behaviour results in a chapter named "5.1"

a correct behaviour would be to have "005.1" or "005.001"

[Red Squirrel]

v16 released, it fixes this issue