css: Use SCSS nesting for message_embed rules block.
css: Use SCSS nesting for message_embed rules block.

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