settings: Do not initialize save_organization_settings in build_page.
settings: Do not initialize save_organization_settings in build_page.

We directly declare the save_organization_settings function instead
of first declaring a variable and then setting it in the build_page
function. This is a prep commit for using save/discard widget in
realm-level defaults section.

zulip/zulip,andersk/zulip,rht/zulip,eeshangarg/zulip,kou/zulip,zulip/zulip,zulip/zulip,eeshangarg/zulip,kou/zulip,rht/zulip,zulip/zulip,andersk/zulip,rht/zulip,kou/zulip,kou/zulip,eeshangarg/zulip,zulip/zulip,zulip/zulip,eeshangarg/zulip,kou/zulip,andersk/zulip,andersk/zulip,andersk/zulip,eeshangarg/zulip,kou/zulip,rht/zulip,rht/zulip,eeshangarg/zulip,rht/zulip,zulip/zulip,eeshangarg/zulip,andersk/zulip,kou/zulip,rht/zulip,andersk/zulip