Fixed Issue with https links

[alz2]

There's an issue with _path2url(self, path) which concats returned https links to http://scholar.google.com/.

For example:

$ python3 scholar.py --author "Margaret Fleck" | grep link.springer
           URL http://scholar.google.com/https://link.springer.com/chapter/10.1007/3-540-61123-1_173
           URL http://scholar.google.com/https://link.springer.com/article/10.1023/A:1008145029462
           URL http://scholar.google.com/https://link.springer.com/chapter/10.1007/3-540-61750-7_36

The actual url should be https://link.springer.com/chapter/10.1007/3-540-61750-7_36