UI breaks when connecting multiple end roads

[zarte13]

I had about 5 parallel roads ending with nothing so I connected them with another road and then the UI broke..,
Citybound version: v0.1.2-714-g589d5fb

Error: unreachable executed
__rust_start_panic in /citybound.daffc617.js 3014768:1
rust_panic in /citybound.daffc617.js 3014650:1
std::panicking::rust_panic_with_hook::h59b410f8f92fb42f in /citybound.daffc617.js 3013906:1
std::panicking::continue_panic_fmt::h78a0e8074db09f28 in /citybound.daffc617.js 3013455:1
rust_begin_unwind in /citybound.daffc617.js 3013327:1
core::panicking::panic_fmt::h5b0d03835cdf4582 in /citybound.daffc617.js 3067666:1
core::option::expect_failed::h7fae801ee47291f1 in /citybound.daffc617.js 3067783:1
Module.STDWEB_PRIVATE.to_js in ../target\wasm32-unknown-unknown\release\citybound_browser.js 139:8
_$LT$citybound_browser..planning_browser..BrowserPlanningUI$u20$as$u20$citybound_common..planning..ui..PlanningUI$GT$::on_proposal_preview_update::h3864f65886013ffa in /citybound.daffc617.js 179165:1
_$LT$kay..instance_store..InstanceStore$LT$A$GT$$GT$::dispatch_packet::h626d3d54aa0244f0 in /citybound.daffc617.js 390884:1
componentWillReceiveProps in ../node_modules\rc-calendar\es\date\DateInput.js 32:2
kay::actor_system::ActorSystem::single_message_cycle::hec9649f478db84eb in /citybound.daffc617.js 2924523:1
std::panicking::try::do_call::hb3aa8fb83236fe23 (.llvm.10913003429600309982) in /citybound.daffc617.js 2890656:1
__rust_maybe_catch_panic in /citybound.daffc617.js 3014760:1
kay::actor_system::ActorSystem::process_all_messages::h1a5414cc236a7084 in /citybound.daffc617.js 2925026:1
_inherits in /citybound.daffc617.js 104187:1
uiTextNode.getAttribute in /citybound.daffc617.js 29994:1
dyncall in ../target\wasm32-unknown-unknown\release\citybound_browser.js 425:11
output in ../target\wasm32-unknown-unknown\release\citybound_browser.js 182:12