portico-signin: Fix character overflow in input.
portico-signin: Fix character overflow in input.

This fixes the characters like “g” and “l” from overflowing the input
bounds while maintaining the previous height of the input box itself.

Fixes: #6665.

punchagan/zulip,showell/zulip,eeshangarg/zulip,brainwane/zulip,kou/zulip,amanharitsh123/zulip,rht/zulip,shubhamdhama/zulip,timabbott/zulip,shubhamdhama/zulip,hackerkid/zulip,rishig/zulip,kou/zulip,showell/zulip,shubhamdhama/zulip,showell/zulip,brockwhittaker/zulip,rht/zulip,verma-varsha/zulip,shubhamdhama/zulip,showell/zulip,rishig/zulip,tommyip/zulip,andersk/zulip,rishig/zulip,zulip/zulip,amanharitsh123/zulip,dhcrzf/zulip,dhcrzf/zulip,eeshangarg/zulip,shubhamdhama/zulip,zulip/zulip,Galexrt/zulip,hackerkid/zulip,rishig/zulip,brainwane/zulip,mahim97/zulip,zulip/zulip,kou/zulip,timabbott/zulip,jackrzhang/zulip,synicalsyntax/zulip,amanharitsh123/zulip,amanharitsh123/zulip,hackerkid/zulip,Galexrt/zulip,Galexrt/zulip,hackerkid/zulip,tommyip/zulip,kou/zulip,synicalsyntax/zulip,brockwhittaker/zulip,Galexrt/zulip,rht/zulip,andersk/zulip,zulip/zulip,tommyip/zulip,verma-varsha/zulip,shubhamdhama/zulip,brockwhittaker/zulip,jackrzhang/zulip,mahim97/zulip,jackrzhang/zulip,kou/zulip,eeshangarg/zulip,punchagan/zulip,brockwhittaker/zulip,timabbott/zulip,rishig/zulip,tommyip/zulip,jackrzhang/zulip,punchagan/zulip,mahim97/zulip,synicalsyntax/zulip,rht/zulip,rht/zulip,dhcrzf/zulip,timabbott/zulip,showell/zulip,brainwane/zulip,dhcrzf/zulip,zulip/zulip,synicalsyntax/zulip,tommyip/zulip,hackerkid/zulip,zulip/zulip,hackerkid/zulip,eeshangarg/zulip,synicalsyntax/zulip,amanharitsh123/zulip,andersk/zulip,mahim97/zulip,kou/zulip,kou/zulip,punchagan/zulip,timabbott/zulip,andersk/zulip,jackrzhang/zulip,brockwhittaker/zulip,andersk/zulip,dhcrzf/zulip,zulip/zulip,andersk/zulip,andersk/zulip,rht/zulip,rht/zulip,brainwane/zulip,eeshangarg/zulip,synicalsyntax/zulip,timabbott/zulip,Galexrt/zulip,verma-varsha/zulip,jackrzhang/zulip,tommyip/zulip,jackrzhang/zulip,rishig/zulip,Galexrt/zulip,eeshangarg/zulip,tommyip/zulip,brockwhittaker/zulip,dhcrzf/zulip,eeshangarg/zulip,dhcrzf/zulip,verma-varsha/zulip,rishig/zulip,punchagan/zulip,showell/zulip,verma-varsha/zulip,Galexrt/zulip,shubhamdhama/zulip,amanharitsh123/zulip,brainwane/zulip,mahim97/zulip,brainwane/zulip,punchagan/zulip,verma-varsha/zulip,showell/zulip,hackerkid/zulip,synicalsyntax/zulip,mahim97/zulip,brainwane/zulip,timabbott/zulip,punchagan/zulip