Added error message when input url is null fixes #116
Added error message when input url is null fixes #116

zulip/zulip-desktop,brainwane/zulip-electron,zulip/zulip-desktop,brainwane/zulip-electron,zulip/zulip-electron,zulip/zulip-desktop,brainwane/zulip-electron,zulip/zulip-desktop,zulip/zulip-electron,zulip/zulip-electron