Realip: fixed uninitialized memory access.
Realip: fixed uninitialized memory access.

Previously, the realip module could be left with uninitialized context after an
error in the ngx_http_realip_set_addr() function.  That context could be later
accessed by $realip_remote_addr and $realip_remote_port variable handlers.

firebase/nginx,firebase/nginx,firebase/nginx,firebase/nginx