Escape spaces in the installation URL (bsc#1201816)

[lslezak]

Problem

• The URL from install.inf might contain unescaped spaces. Spaces are not allowed in URL and should be escaped.
• See https://bugzilla.suse.com/show_bug.cgi?id=1201816#c10, https://bugzilla.suse.com/show_bug.cgi?id=1201816#c26

Solution

• As a quick and simple fix just replace all spaces with the percent encoded values
• This does not need any change in linuxrc and can be deployed as a self-update

Testing

• Tested manually

[yast-bot]

:heavy_check_mark: Internal Jenkins job #5 successfully finished :heavy_check_mark: Created IBS submit request #286680