fix: if a single token is supported, automatically select it

It covers cases such as bitcoin so that the user
doesn't have to perform an extra action to select
the only supported token

components/checkout/pay/CryptoAssetSelector.vue

@@ -74,6 +74,12 @@ const hint = computed(() => {
 
   return `${t('home.plans.tiers.step_3.labels.token_contract')} ${address}`;
 });
+
+watch(tokenItems, (tokens) => {
+  if (tokens.length === 1) {
+    set(modelValue, tokens[0].id);
+  }
+});
 </script>
 
 <template>