Well ... there is an external way around this.

My search engine of choice is Duckduckgo.

Go to the Duckduckgo site and download/install the Android app.
During the set-up it will ask you to associate a browser with Duckduckgo.
Select Opera for Android.

In your apps listing you will have a link to the Duckduckgo app.
Drag it to your preferred display screen (for me it is the device's home screen).

Now each time I want to do a web search (bypassing the inbuilt search engines of Opera) I simply tap on the Duckduckgo icon and that's it! Best of both worlds - Duckduckgo and Opera Android.

So far it has been working for me. Hope this helps others.

OziIan