nginx: fix geoip2 dependency on mod ngx_stream

Since the geoip2 package contains both `http` and `stream` versions. It
requires the module `ngx_stream` be installed and loaded and produces
the error:

```
2024/04/12 18:38:18 [emerg] 4402#0: dlopen()
"/usr/lib/nginx/modules/ngx_stream_geoip2_module.so" failed (Error
relocating /usr/lib/nginx/modules/ngx_stream_geoip2_module.so:
ngx_stream_complex_value: symbol not found) in
/etc/nginx/module.d/ngx_stream_geoip2.module:1 nginx: configuration file
/etc/nginx/uci.conf test failed
```

Add dependency so it's built at build time and installed automatically
by `opkg`

Signed-off-by: Sean Khan <datapronix@protonmail.com>