BitQuick is no longer active

[timbalabuch]

The link to https://bitquick.co/ is no longer valid as the site is no longer active.
I will remove this link from the exchanges page to keep the content up-to-date.

PR #4344

[megha-66]

@timbalabuch instead of removing, we can just replace the site url with the correct one.

PR #4346

[timbalabuch]

@megha-66 yes! thanks for the catch.