message-header: Bump up the opcaity of icons.
message-header: Bump up the opcaity of icons.

Because of visibility issues both in day and night mode this commit
will increase the opacity of recipient_bar_controls icons from 0.1 to 0.2.

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