ftp: fix invalid pointer dereference in getftp() (tiny change)

The pointer respline in use after being passed to ftp_response() may be
uninitialized if ftp_response() fails.  Ensure that respline be used
after checking the return value of ftp_response().
contrib: Added script contrib/check-hard to check Wget status

This script automates some tests, e.g. testing with and without valgrind,
using different configure options. It is aimed at developers to execute
before pushing commits.
Revert "ChangeLog: Move all ChangeLog files to .pre-gitlog"

This reverts commit fcd3b3c473be25c4967fd8139d976e76faaef1b6.

Turns out that removing the ChangeLog files causes the Wget build to
fail. While this issue is investigated and sorted out, the commit is
reversed to allow people to be able to build Wget from master