Check for availableTokens undefined before use

Author: rBurgett

index.js

@@ -1563,6 +1563,10 @@ const getLocalTokens = async function() {
 const getNetworkTokens = async function() {
   let filteredTokens;
   if(unconnected) {
+    if(!availableTokens) {
+      const manifestData = getManifest();
+      availableTokens = new Set(manifestData.map(d => d.ticker));
+    }
     filteredTokens = [...availableTokens.values()];
   } else {
     const networkTokens = await sn.dxGetNetworkTokens();