ui_install.md: Merged 2 FAQ entries about Postgres connection limits.
ui_install.md: Merged 2 FAQ entries about Postgres connection limits.

ceos-seo/data_cube_ui,ceos-seo/data_cube_ui,ceos-seo/data_cube_ui,ceos-seo/data_cube_ui,ceos-seo/data_cube_ui