Connection error handling

[klausweiss]

Problem:
When hostname is unreachable during initializing repository as follows:

agh-git klausweiss@student.agh.edu.pl init tw-5

And the following occurs:

ssh: Could not resolve hostname student.agh.edu.pl: Temporary failure in name resolution

The links are printed anyway as if nothing happened:

ssh:  ssh://klausweiss@student.agh.edu.pl/~/git/tw-5.git
http: http://student.agh.edu.pl/~klausweiss/git/tw-5.git

And the program returns 0.

To do:
Return non-zero status when ssh fails and do not print the urls.