Should not use for loop declarations

[sergey-dryabzhinsky]

gcc-4.8 in Ubuntu 14.04 fails in hiredis code with:

/home/sergey/debuild/nginx/nginx-1.20/nginx/nginx-1.20.2/debian/modules/http-nchan/src/store/redis/hiredis/read.c: In function ‘redisReaderFree’:
/home/sergey/debuild/nginx/nginx-1.20/nginx/nginx-1.20.2/debian/modules/http-nchan/src/store/redis/hiredis/read.c:646:9: error: ‘for’ loop initial declarations are only allowed in C99 mode
         for (int i = 0; i < r->tasks; i++) {
         ^

I think that can be healed via CFLAGS declaration in config.
Just add these lines after have= ...:

CFLAGS="$CFLAGS -std=gnu99"

This should work fine with gcc-4.4+

Or move i declaration from loop if you're supporting hiredis code.