Replace UTF-8 no-break space to ASCII space

UTF-8 no-break space causes C4819 warning in MSVC with CP932.

Change-Id: I83a6ea6d060d132d21d8ea3141051f850d0e6bd2
Reviewed-on: https://gerrit.libreoffice.org/8628
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>