[one-users] remove the comment from context.sh

[Shi Jin]

Hi there,

When I do the contexualization for the Windows VMs, I need to read the
content of the context.sh file from the ISO image.
However, this file contains a comment at its first line:
# Context variables generated by OpenNebula
This can be ignored on Linux by a shell script but NOT on Windows by a VBScript.
The rest of the variable assignments have the same syntax on both systems.
So maybe the easiest solution is to remove this comment line. In
addition, to make it more universal,we may rename the file from
context.sh into context.txt or purely context.

Otherwise, we could provide different content files for different OS.
I hope this is easy to do as well.
Thank you very much.

-- 
Shi Jin, Ph.D.