install-node: Fix errors in case node or npm is not installed.
install-node: Fix errors in case node or npm is not installed.

shubhamdhama/zulip,shubhamdhama/zulip,zulip/zulip,andersk/zulip,tommyip/zulip,verma-varsha/zulip,vaidap/zulip,jrowan/zulip,rishig/zulip,andersk/zulip,hackerkid/zulip,punchagan/zulip,jrowan/zulip,tommyip/zulip,hackerkid/zulip,brainwane/zulip,eeshangarg/zulip,tommyip/zulip,brockwhittaker/zulip,jackrzhang/zulip,zulip/zulip,jackrzhang/zulip,vabs22/zulip,brockwhittaker/zulip,Galexrt/zulip,brainwane/zulip,shubhamdhama/zulip,hackerkid/zulip,brockwhittaker/zulip,rht/zulip,brainwane/zulip,brainwane/zulip,punchagan/zulip,jackrzhang/zulip,amanharitsh123/zulip,kou/zulip,amanharitsh123/zulip,jackrzhang/zulip,vaidap/zulip,timabbott/zulip,showell/zulip,Galexrt/zulip,showell/zulip,hackerkid/zulip,synicalsyntax/zulip,vabs22/zulip,timabbott/zulip,tommyip/zulip,verma-varsha/zulip,rishig/zulip,showell/zulip,punchagan/zulip,rishig/zulip,rht/zulip,vabs22/zulip,timabbott/zulip,verma-varsha/zulip,tommyip/zulip,eeshangarg/zulip,mahim97/zulip,rishig/zulip,hackerkid/zulip,dhcrzf/zulip,verma-varsha/zulip,jackrzhang/zulip,mahim97/zulip,jackrzhang/zulip,jrowan/zulip,timabbott/zulip,punchagan/zulip,zulip/zulip,eeshangarg/zulip,brockwhittaker/zulip,verma-varsha/zulip,eeshangarg/zulip,jrowan/zulip,showell/zulip,kou/zulip,hackerkid/zulip,kou/zulip,jrowan/zulip,eeshangarg/zulip,shubhamdhama/zulip,showell/zulip,dhcrzf/zulip,synicalsyntax/zulip,Galexrt/zulip,rht/zulip,tommyip/zulip,zulip/zulip,timabbott/zulip,synicalsyntax/zulip,dhcrzf/zulip,vabs22/zulip,dhcrzf/zulip,rht/zulip,rht/zulip,shubhamdhama/zulip,andersk/zulip,Galexrt/zulip,vaidap/zulip,amanharitsh123/zulip,mahim97/zulip,timabbott/zulip,hackerkid/zulip,dhcrzf/zulip,kou/zulip,brainwane/zulip,synicalsyntax/zulip,brainwane/zulip,andersk/zulip,andersk/zulip,synicalsyntax/zulip,jrowan/zulip,synicalsyntax/zulip,tommyip/zulip,zulip/zulip,kou/zulip,rht/zulip,mahim97/zulip,zulip/zulip,mahim97/zulip,kou/zulip,brainwane/zulip,andersk/zulip,vaidap/zulip,punchagan/zulip,rishig/zulip,vaidap/zulip,mahim97/zulip,showell/zulip,punchagan/zulip,dhcrzf/zulip,rht/zulip,rishig/zulip,amanharitsh123/zulip,andersk/zulip,shubhamdhama/zulip,brockwhittaker/zulip,showell/zulip,verma-varsha/zulip,synicalsyntax/zulip,dhcrzf/zulip,amanharitsh123/zulip,vabs22/zulip,amanharitsh123/zulip,punchagan/zulip,zulip/zulip,Galexrt/zulip,kou/zulip,timabbott/zulip,jackrzhang/zulip,brockwhittaker/zulip,eeshangarg/zulip,shubhamdhama/zulip,vabs22/zulip,Galexrt/zulip,rishig/zulip,eeshangarg/zulip,Galexrt/zulip,vaidap/zulip