Fix double --open_browser (by imachug)

start.py

@@ -9,7 +9,8 @@ import zeronet
 
 
 def main():
-    sys.argv = [sys.argv[0]]+["--open_browser", "default_browser"]+sys.argv[1:]
+    if "--open_browser" not in sys.argv:
+        sys.argv = [sys.argv[0]] + ["--open_browser", "default_browser"] + sys.argv[1:]
     zeronet.main()
 
 if __name__ == '__main__':