[BUGFIX] EM installs outdated versions of depending extensions

When installing an extension with a dependency to another extension,
which is not available on the server, EM retrieves it from TER. However,
by mistake it always retrieves the oldest version, not the newest.

Change-Id: I518cd5e4521d5ad1b578e342175f8b542ef42d02
Resolves: #29243
Releases: 4.6, 4.5
Reviewed-on: http://review.typo3.org/5574
Reviewed-by: Josef Florian Glatz
Tested-by: Josef Florian Glatz
Reviewed-by: Xavier Perseguers
Tested-by: Xavier Perseguers