Remove half-baked compatibility code for old browsers.

static/sfu.js

@@ -1217,13 +1217,16 @@ async function negotiate(id) {
     let c = up[id];
     if(!c)
         throw new Error('unknown connection');
+
+    if(typeof(c.pc.getTransceivers) !== 'function')
+        throw new Error('Browser too old, please upgrade');
+
     let offer = await c.pc.createOffer({});
     if(!offer)
         throw(new Error("Didn't create offer"));
     await c.pc.setLocalDescription(offer);
 
     // mids are not known until this point
-    if(typeof(c.pc.getTransceivers) === 'function') {
     c.pc.getTransceivers().forEach(t => {
         if(t.sender && t.sender.track) {
             let label = c.labels[t.sender.track.id];
@@ -1233,11 +1236,6 @@ async function negotiate(id) {
                 console.warn("Couldn't find label for track");
         }
     });
-    } else {
-        console.warn('getTransceivers undefined');
-        displayWarning('getTransceivers undefined, please upgrade your browser');
-        // let the server deal with the mess
-    }
 
     send({
         type: 'offer',