XSP data downloading script issues

Hi, there are several issues with the `data_download.sh` script in the xsp subfolder.

1. From the download for scholar data onwards, the `wget` commands are not valid. They need to be edited to remove the ''blob'' in the url.
Example:
Original: `wget https://raw.githubusercontent.com/jkkummerfeld/text2sql-data/blob/master/data/scholar.json`
Edited: `wget https://raw.githubusercontent.com/jkkummerfeld/text2sql-data/master/data/scholar.json`

2. The `wget` commands for downloading all the schemas are due to the above issue also. Using the provided `wget`s will give us an invalid xml file with no schema information