Fix URL string when fetching homebrew content

[Jyers]

Description:

Small change to account for the fact that window.location.protocol always contains a colon, ie "https:" not "https".
This produced an error in fetching "homebrew.orcbrew" as the URL was malformed.
Remove the colon fixes this. This is the case for all browsers and systems.

Checklist:

• The code change is tested and works locally.
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation if necessary
• There is no commented out code in this PR.
• My changes generate no new warnings (check the console)

[datdamnzotz]

Fixes #639