scripts/functions: remove messages about failed downloads

When downloading via svn/cvs/... an attempt to retrieve from the
mirror is made. If the mirror does not have the required tarball,
an error message is printed. This is misleading, as the download
may later succeed via svn/cvs/...

Remove the messages about failed downloads altogether.

At the same time, use "if ... then ... fi" instead of "... && ..."

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>

 #!/bin/sh

 SKIP_ME="### CT_NG SKIP ME ###"

 skip_me=$(($(cat "${0}" |@@grep@@ --binary-files=text -o -b -E "^${SKIP_ME}$" |cut -d : -f 1)+${#SKIP_ME}+1))

 dd if="${0}" bs=${skip_me} skip=1 2>/dev/null |bzcat

 exit 0

 ### CT_NG SKIP ME ###