tls: fix test-https-client-reject fails

Fixes #2417.

lib/tls.js

@@ -719,10 +719,13 @@ SecurePair.prototype.maybeInitFinished = function() {
 
 
 SecurePair.prototype.destroy = function() {
+  if (this._doneFlag) {
+    return;
+  }
+
   var self = this;
   var error = this.ssl.error;
 
-  if (!this._doneFlag) {
   this._doneFlag = true;
   this.ssl.error = null;
   this.ssl.close();
@@ -744,7 +747,6 @@ SecurePair.prototype.destroy = function() {
     }
     this.emit('error', error);
   }
-  }
 };