It's nothing to do with the number of URLs... It's how they're formatted:

Since there are no spaces, the URL parser thinks the entire string http://www.google.com...Could
is a URL - and of course, this is not a valid URL!
There are a few possible work-arounds here:
Leave off the http://
This is the easiest, since the URL parser will just ignore it - but it also changes the actual error message, so this is somewhat undesirable. That said, in this specific case you shouldn't actually be passing "http" to telnet anyway.
Use code formatting for the URL. Surround the URL in backtics, and the URL parser will ignore it. Example:
Connecting To http://www.google.com
...Could not open connection to the host, on port 23: Connect failed
Put the entire error in a code block. By indenting four spaces instead of using the > prefix, the error message will be rendered as code and ignored by the URL parser. The downside of this is that it will all appear on a single line:
Connecting To http://www.google.com...Could not open connection to the host, on port 23: Connect failed
Use HTML blockquote syntax. By eschewing Markdown entirely, you can obtain much greater control over what is rendered. So writing this:
<blockquote>Connecting To http://www.google.com...Could not open connection to the host, on port 23: Connect failed</blockquote>
...produces this:
Connecting To http://www.google.com...Could not open connection to the host, on port 23: Connect failed
Note that you'll have to escape any invalid HTML in the quote in order for this to work.