BUG/MEDIUM: stats: properly initialize the scope before dumping stats

Issuing a "show sess all" prior to a "show stat" on the CLI results in no
proxy being dumped because the scope_len union member was not properly
reinitialized.

This fix must be backported into 1.5.
(cherry picked from commit 6bcb95da5b9cb143088102b460c7bcb37c1b3d81)
1 file changed