Knowledge - Trim leading spaces in knowledge website links.

[sangee2004]

Steps to reproduce the problem:

1. Create an agent with knowledge file from website having leading spaces like https://docs.gptscript.ai/
2. Notice that this results in no sync being initiated and no error message presented to the user.
3. When you close the webstite knowldege page and renter it , notice that the url has "https:\" appended to it - https:// https://docs.gptscript.ai/

Expected Behavior:
Trim leading spaces in knowledge website links before it gets saved.

[sangee2004]

This issue is still seen when testing with latest version of builds:

Create an agent with knowledge file from website having leading spaces like https://docs.gptscript.ai/

This results in the following error:

[sangee2004]

Issue with leading spaces is addressed when testing with latest builds.