fix add_contact and rename_contact

Fix when crashing if print_name is null

Fix it to work on current stable gentoo.

Fixed random crashes and crash on group link request

- (Random crashes) Fixed uninitialized variable prompt_was; please, use static variables to make life easier to everyone.
- Removed duplicate line 2138. The print_start/print_end mechanism is weak, there's a lot of redundant code and bugs are hard to catch.