move trace loading check from ui to debugger

src/app/debugger/debugger/debugger.js

@@ -81,6 +81,10 @@ Debugger.prototype.debug = function (blockNumber, txNumber, tx, loadingCb) {
   const self = this
   let web3 = this.executionContext.web3()
 
+  if (this.debugger.traceManager.isLoading) {
+    return
+  }
+
   if (tx) {
     if (!tx.to) {
       tx.to = traceHelper.contractCreationToken('0')

src/app/debugger/debuggerUI.js

@@ -113,10 +113,6 @@ class DebuggerUI {
   startDebugging (blockNumber, txNumber, tx) {
     const self = this
 
-    if (this.debugger.traceManager.isLoading) {
-      return
-    }
-
     this.transactionDebugger.debug(blockNumber, txNumber, tx, () => {
       self.stepManager = new StepManagerUI(this.transactionDebugger.step_manager)
       self.vmDebugger = new VmDebugger(this.transactionDebugger.vmDebuggerLogic)