push notifs: Simplify content-truncation code slightly.
push notifs: Simplify content-truncation code slightly.

This should be a pure refactor.

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