BUG/MINOR: ssl_ckch: Fix possible uninitialized value in show_cert I/O handler

Commit 3e94f5d4b ("BUG/MINOR: ssl_ckch: Dump cert transaction only once if
show command yield") introduced a regression leading to a build error
because of a possible uninitialized value. It is now fixed.

This patch must be backported as far as 2.2.
1 file changed