message_edit: Fix timer text not decrementing. 
message_edit: Fix timer text not decrementing. 

This fixes a regression introduced in e6369fc, where we simply lost the `--` part.

Fixes #3720.

rishig/zulip,vaidap/zulip,jainayush975/zulip,showell/zulip,zulip/zulip,zulip/zulip,dhcrzf/zulip,zulip/zulip,susansls/zulip,jrowan/zulip,dhcrzf/zulip,jphilipsen05/zulip,samatdav/zulip,vabs22/zulip,jackrzhang/zulip,brainwane/zulip,souravbadami/zulip,showell/zulip,vabs22/zulip,samatdav/zulip,andersk/zulip,dattatreya303/zulip,jainayush975/zulip,vaidap/zulip,ryanbackman/zulip,amanharitsh123/zulip,jphilipsen05/zulip,jrowan/zulip,zulip/zulip,rishig/zulip,eeshangarg/zulip,JPJPJPOPOP/zulip,dattatreya303/zulip,punchagan/zulip,rht/zulip,JPJPJPOPOP/zulip,ryanbackman/zulip,shubhamdhama/zulip,rht/zulip,mahim97/zulip,mahim97/zulip,Galexrt/zulip,JPJPJPOPOP/zulip,brockwhittaker/zulip,christi3k/zulip,hackerkid/zulip,kou/zulip,punchagan/zulip,brainwane/zulip,eeshangarg/zulip,Galexrt/zulip,dawran6/zulip,Galexrt/zulip,ryanbackman/zulip,jrowan/zulip,showell/zulip,rht/zulip,vaidap/zulip,JPJPJPOPOP/zulip,hackerkid/zulip,jackrzhang/zulip,punchagan/zulip,jackrzhang/zulip,PhilSk/zulip,christi3k/zulip,amanharitsh123/zulip,jrowan/zulip,blaze225/zulip,vaidap/zulip,PhilSk/zulip,brockwhittaker/zulip,jackrzhang/zulip,ryanbackman/zulip,dattatreya303/zulip,showell/zulip,susansls/zulip,shubhamdhama/zulip,zulip/zulip,christi3k/zulip,verma-varsha/zulip,samatdav/zulip,rishig/zulip,tommyip/zulip,dattatreya303/zulip,brockwhittaker/zulip,jackrzhang/zulip,timabbott/zulip,vabs22/zulip,tommyip/zulip,dattatreya303/zulip,brainwane/zulip,andersk/zulip,rht/zulip,amanharitsh123/zulip,timabbott/zulip,aakash-cr7/zulip,j831/zulip,synicalsyntax/zulip,christi3k/zulip,kou/zulip,brainwane/zulip,kou/zulip,PhilSk/zulip,timabbott/zulip,Galexrt/zulip,amanharitsh123/zulip,j831/zulip,verma-varsha/zulip,blaze225/zulip,aakash-cr7/zulip,JPJPJPOPOP/zulip,rht/zulip,eeshangarg/zulip,susansls/zulip,synicalsyntax/zulip,shubhamdhama/zulip,jackrzhang/zulip,andersk/zulip,brainwane/zulip,brainwane/zulip,tommyip/zulip,rishig/zulip,SmartPeople/zulip,verma-varsha/zulip,j831/zulip,souravbadami/zulip,susansls/zulip,shubhamdhama/zulip,dawran6/zulip,SmartPeople/zulip,PhilSk/zulip,mahim97/zulip,dawran6/zulip,blaze225/zulip,blaze225/zulip,samatdav/zulip,synicalsyntax/zulip,PhilSk/zulip,andersk/zulip,brockwhittaker/zulip,verma-varsha/zulip,souravbadami/zulip,PhilSk/zulip,jainayush975/zulip,jphilipsen05/zulip,dawran6/zulip,jainayush975/zulip,dhcrzf/zulip,brockwhittaker/zulip,synicalsyntax/zulip,vaidap/zulip,timabbott/zulip,kou/zulip,blaze225/zulip,susansls/zulip,jrowan/zulip,Galexrt/zulip,SmartPeople/zulip,samatdav/zulip,punchagan/zulip,SmartPeople/zulip,andersk/zulip,tommyip/zulip,jphilipsen05/zulip,hackerkid/zulip,rishig/zulip,shubhamdhama/zulip,verma-varsha/zulip,mahim97/zulip,j831/zulip,eeshangarg/zulip,showell/zulip,christi3k/zulip,dhcrzf/zulip,souravbadami/zulip,andersk/zulip,vabs22/zulip,mahim97/zulip,dhcrzf/zulip,JPJPJPOPOP/zulip,hackerkid/zulip,eeshangarg/zulip,kou/zulip,andersk/zulip,vabs22/zulip,jphilipsen05/zulip,dawran6/zulip,showell/zulip,rishig/zulip,hackerkid/zulip,vaidap/zulip,dattatreya303/zulip,punchagan/zulip,aakash-cr7/zulip,souravbadami/zulip,timabbott/zulip,SmartPeople/zulip,SmartPeople/zulip,jainayush975/zulip,eeshangarg/zulip,hackerkid/zulip,rht/zulip,mahim97/zulip,samatdav/zulip,jrowan/zulip,souravbadami/zulip,brockwhittaker/zulip,christi3k/zulip,Galexrt/zulip,susansls/zulip,amanharitsh123/zulip,synicalsyntax/zulip,jphilipsen05/zulip,tommyip/zulip,dhcrzf/zulip,eeshangarg/zulip,synicalsyntax/zulip,hackerkid/zulip,dawran6/zulip,punchagan/zulip,Galexrt/zulip,brainwane/zulip,punchagan/zulip,amanharitsh123/zulip,zulip/zulip,shubhamdhama/zulip,jackrzhang/zulip,kou/zulip,showell/zulip,dhcrzf/zulip,rishig/zulip,tommyip/zulip,j831/zulip,kou/zulip,ryanbackman/zulip,blaze225/zulip,aakash-cr7/zulip,rht/zulip,synicalsyntax/zulip,j831/zulip,timabbott/zulip,ryanbackman/zulip,tommyip/zulip,vabs22/zulip,aakash-cr7/zulip,timabbott/zulip,aakash-cr7/zulip,verma-varsha/zulip,jainayush975/zulip,shubhamdhama/zulip,zulip/zulip