fix(strophe.jingle.js): exception on ICE config modification

If ICE config object gets modified while there's any native
PeerConnection instance holding a reference, it will cause
an exception about final object being modified.

It happens when trying to reconnect XMPP Websocket on RN and
is caused by the fact that new TURN config is fetched after
the connection is re-established.

modules/xmpp/strophe.jingle.js

             logger.info(
                 `Marking session from ${fromJid
                 } as ${isP2P ? '' : '*not*'} P2P`);
+
+            const iceConfig = isP2P ? this.p2pIceConfig : this.jvbIceConfig;
+
             sess
                 = new JingleSessionPC(
                     $(iq).find('jingle').attr('sid'),
                     fromJid,
                     this.connection,
                     this.mediaConstraints,
-                    isP2P ? this.p2pIceConfig : this.jvbIceConfig,
+
+                    // Makes a copy in order to prevent exception thrown on RN when either this.p2pIceConfig or
+                    // this.jvbIceConfig is modified and there's a PeerConnection instance holding a reference
+                    JSON.parse(JSON.stringify(iceConfig)),
                     isP2P,
                     /* initiator */ false);