stream settings: Move stream-email-box from regular_subscription_settings.
stream settings: Move stream-email-box from regular_subscription_settings.

`stream-email-box` doesn't fit into `regular_subscription_settings` div,
therefore moved `stream-email-box` out of it.

eeshangarg/zulip,andersk/zulip,eeshangarg/zulip,punchagan/zulip,hackerkid/zulip,shubhamdhama/zulip,shubhamdhama/zulip,eeshangarg/zulip,eeshangarg/zulip,andersk/zulip,hackerkid/zulip,kou/zulip,brainwane/zulip,rht/zulip,andersk/zulip,kou/zulip,shubhamdhama/zulip,brainwane/zulip,showell/zulip,brainwane/zulip,hackerkid/zulip,timabbott/zulip,hackerkid/zulip,brainwane/zulip,andersk/zulip,synicalsyntax/zulip,rht/zulip,punchagan/zulip,rht/zulip,zulip/zulip,kou/zulip,brainwane/zulip,eeshangarg/zulip,andersk/zulip,shubhamdhama/zulip,rht/zulip,synicalsyntax/zulip,rht/zulip,punchagan/zulip,kou/zulip,rht/zulip,andersk/zulip,rht/zulip,punchagan/zulip,shubhamdhama/zulip,zulip/zulip,kou/zulip,punchagan/zulip,synicalsyntax/zulip,shubhamdhama/zulip,showell/zulip,eeshangarg/zulip,hackerkid/zulip,timabbott/zulip,zulip/zulip,zulip/zulip,hackerkid/zulip,showell/zulip,punchagan/zulip,showell/zulip,zulip/zulip,zulip/zulip,timabbott/zulip,timabbott/zulip,synicalsyntax/zulip,brainwane/zulip,synicalsyntax/zulip,synicalsyntax/zulip,zulip/zulip,timabbott/zulip,showell/zulip,kou/zulip,eeshangarg/zulip,timabbott/zulip,shubhamdhama/zulip,showell/zulip,brainwane/zulip,showell/zulip,kou/zulip,timabbott/zulip,hackerkid/zulip,punchagan/zulip,synicalsyntax/zulip,andersk/zulip