Remove getCapabilities call for guest users (#2100)

Author: Germain

spec/unit/matrix-client.spec.js

@@ -713,7 +713,6 @@ describe("MatrixClient", function() {
     describe("guest rooms", function() {
         it("should only do /sync calls (without filter/pushrules)", function(done) {
             httpLookups = []; // no /pushrules or /filterw
-            httpLookups.push(CAPABILITIES_RESPONSE);
             httpLookups.push({
                 method: "GET",
                 path: "/sync",

src/client.ts

@@ -1041,7 +1041,9 @@ export class MatrixClient extends EventEmitter {
             this.syncApi.stop();
         }
 
-        await this.getCapabilities(true);
+        if (!this.isGuest()) {
+            await this.getCapabilities(true);
+        }
 
         // shallow-copy the opts dict before modifying and storing it
         this.clientOpts = Object.assign({}, opts) as IStoredClientOpts;