Fix parsing wml files, if debian version and fixed version are located on different lines

Script parses wml files line by line. And in most cases it can't find debian release and fixed version in one line, because this info looks like:

"

For the stable distribution (buster), this problem has been fixed in version 3.0.12-0+deb10u1.

"

So current code ignores multi-line block and doesn't update final dict.