version: Update for Zulip Desktop v5.1.0 release.
version: Update for Zulip Desktop v5.1.0 release.

Update the zulip-desktop download link for the latest v5.3.0 release
This only updates zulipchat.com/apps/ downloads link.

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