BUG/MEDIUM: ssl/crt-list: fix error when no file found

When a file from a crt-list was not found, this one was ignored silently
letting HAProxy starts without it.

This bug was introduced by 47da821 ("MEDIUM: ssl: emulates the
multi-cert bundles in the crtlist").

This commit adds a found variable which is checked once we tried every
bundle combination so we can exits with an error if none were found.

Must be backported in 2.3.
1 file changed