Fix semicolons in TS files

This updates the linting config to include the semi fix in
https://github.com/matrix-org/eslint-plugin-matrix-org/pull/8. The various semi
errors have been auto-fixed.

src/webrtc/callEventHandler.ts

@@ -87,7 +87,7 @@ export class CallEventHandler {
             }
             this.callEventBuffer = [];
         }
-    }
+    };
 
     private onEvent = (event: MatrixEvent) => {
         this.client.decryptEventIfNeeded(event);
@@ -117,7 +117,7 @@ export class CallEventHandler {
                 }
             });
         }
-    }
+    };
 
     private eventIsACall(event: MatrixEvent): boolean {
         const type = event.getType();