Issues with IEEE full-text importer.

I have tested the latest master version from http://builds.jabref.org/master/JabRef--master--latest.jar on Windows 7 and the following problem is encountered.

JabRef version 4.2-dev on Windows 7 Enterprise (build 7601 service pack:1)

Steps to reproduce:

1. Use Jabref on a network with full-text access to IEEExplore articles (such as a university's network)
2. Start a new library with the following bibtex entry

@inproceedings{Morabito2017,
author = {Morabito, Bruno and Klein, Reinhardt and Findeisen, Rolf},
booktitle = {2017 American Control Conference (ACC)},
doi = {10.23919/ACC.2017.7963481},
isbn = {978-1-5090-5992-8},
month = {may},
pages = {3457--3462},
publisher = {IEEE},
title = {{Real time feasibility and performance of moving horizon estimation for Li-ion batteries based on first principles electrochemical models}},
url = {http://ieeexplore.ieee.org/document/7963481/},
year = {2017}
}

3. Select this reference entry within Jabref and hit Alt + F7 or go to Quality -> Look up full text documents
4. After a while, the following pop-up dialog box opens
   No full text document found for entry Morabito2017
5. Expected behavior: Navigate to this same URL http://ieeexplore.ieee.org/document/7963481/. This works perfectly fine and full-text PDF can be manually downloaded. The auto downloader should have obtained this PDF and linked it to the citation entry.