Remove "bad http" and "mailto url" messages

Two reasons:
1. The meaning of the "http" message is unclear. The description
   talks about "http and https" but the message doesn't say anything
   about https.
2. I think it's pointless to repeat the protocol in the message. The
   user can't do anything with this information.
3. With all the new protocols added it's overkill to add that many
   messages. The protocol needs to be a parameter. Which is not
   needed at the moment, see 2.

Change-Id: Ib7dde4edf7814fd7e6ea884823fb2383d7e95e6b
Merge "Remove "bad http" and "mailto url" messages"