ApiRequest: Clone the request options before modifying them

With the introduction of mwApiServer, ApiRequest.request started
modifying the request options object before issuing a request to the MW
API. However, the object itself is a property of its sub-classes, which
means that ApiRequest.request was modifying permanently the URI. Hence,
clone the request options object before modifying it.

Bug: T153797
Change-Id: Ibf4cf2fdab74d742c66aedc82379a57def91440a

lib/mw/ApiRequest.js

@@ -272,10 +272,11 @@ util.inherits(ApiRequest, events.EventEmitter);
 var httpAgent = null;
 var httpsAgent = null;
 
-ApiRequest.prototype.request = function(options, callback) {
+ApiRequest.prototype.request = function(requestOpts, callback) {
 	var env = this.env;
 	var proxy = this.proxy;
 	var mwApiServer = this.mwApiServer;
+	var options = Object.assign({}, requestOpts);
 
 	// this is a good place to put debugging statements
 	// if you want to watch network requests.