Merge pull request #2 from EmbeddedMike/master

handled  option 'url: false'

Author: evilebottnawi

src/BrowserSyncDevHotWebpackPlugin.js

@@ -52,10 +52,22 @@ class BrowserSyncDevHotWebpackPlugin {
                     middleware: this.middleware(),
                     proxyReq: [
                         (proxyReq) => {
-                            proxyReq.setHeader('X-Browser-Sync-URL-Local', browserSyncURLLocal);
-                            proxyReq.setHeader('X-Browser-Sync-URL-External', browserSyncURLExternal);
-                            proxyReq.setHeader('X-Browser-Sync-URL-UI', browserSyncURLUI);
-                            proxyReq.setHeader('X-Browser-Sync-URL-UI-External', browserSyncURLUIExternal);
+                            if (browserSyncURLLocal) {
+                                proxyReq.setHeader('X-Browser-Sync-URL-Local', browserSyncURLLocal);
+                            }
+
+                            if (browserSyncURLExternal) {
+                                proxyReq.setHeader('X-Browser-Sync-URL-External', browserSyncURLExternal);
+                            }
+
+                            if (browserSyncURLUI) {
+                                proxyReq.setHeader('X-Browser-Sync-URL-UI', browserSyncURLUI);
+                            }
+
+                            if (browserSyncURLUIExternal) {
+                                proxyReq.setHeader('X-Browser-Sync-URL-UI-External', browserSyncURLUIExternal);
+                            }
+
                             proxyReq.setHeader('X-Dev-Middleware', 'On');
                             proxyReq.setHeader('X-Hot-Middleware', 'On');
                         }