kio ftp uses absolute paths with SIZE command

[AZ]

kio-ftp should use relative paths with SIZE command whenever possible.

This was already fixed 2014 in KDE 4.14.2, but is broken in current ubuntu kde.

https://cgit.kde.org/kdelibs.git/commit/?id=d6453435f0d475e16b2512782b9b3e40bb603da1

Wireshark FTP Trace:

220 SwiFTP 2.11.3 ready
USER ftp
331 Send password
PASS *secret*
230 Access granted
SYST
215 UNIX Type: L8
PWD
257 "/"
cwd /DCIM/Camera/20160729_102840_HDR.jpg
550 Can't CWD to invalid directory
cwd /DCIM/Camera
250 CWD successful
TYPE I
200 Binary type set
PASV
227 Entering Passive Mode (172,16,3,20,210,32).
list 20160729_102840_HDR.jpg
150 Opening BINARY mode data connection for file list
226 Data transmission OK
SIZE /DCIM/Camera/20160729_102840_HDR.jpg
550 No directory traversal allowed in SIZE param
cwd /DCIM/Camera/20160729_102840_HDR.jpg
550 Can't CWD to invalid directory
PASV
227 Entering Passive Mode (172,16,3,20,169,255).
retr /DCIM/Camera/20160729_102840_HDR.jpg
150 Sending file
226 Transmission finished

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: kio 5.18.0-0ubuntu1
ProcVersionSignature: Ubuntu 4.4.0-53.74-generic 4.4.30
Uname: Linux 4.4.0-53-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.4
Architecture: amd64
CurrentDesktop: KDE
Date: Thu Dec 22 10:17:55 2016
SourcePackage: kio
UpgradeStatus: Upgraded to xenial on 2016-04-22 (243 days ago)