wireproto: properly report server Abort during 'getbundle' Previously Abort raised during 'getbundle' call poorly reported (HTTP-500 for http, some scary messages for ssh). Abort error have been properly reported for "push" for a long time, there is not reason to be different for 'getbundle'. We properly catch such error and report them back the best way available. For bundle, we issue a valid bundle2 reply (as expected by the client) with an 'error:abort' part. With bundle1 we do as best as we can depending of http or ssh.