Upstream: fixed unexpected inheritance into limit_except blocks.

Upstream: fixed unexpected inheritance into limit_except blocks.

The proxy_pass directive and other handlers are not expected to be inherited
into nested locations, but there is a special code to inherit upstream
handlers into limit_except blocks, as well as a configuration into if{}
blocks.  This caused incorrect behaviour in configurations with nested
locations and limit_except blocks, like this:

    location / {
        proxy_pass http://u;

        location /inner/ {
            # no proxy_pass here

            limit_except GET {
                # nothing
            }
        }
    }

In such a configuration the limit_except block inside "location /inner/"
unexpectedly used proxy_pass defined in "location /", while it shouldn't.
Fix is to avoid inheritance of conf->upstream.upstream (and
conf->proxy_lengths) into locations which don't have noname flag.