fix(bundle): don't export operators twice (#4310)

Author: alan-agius4

compat/umd.ts

@@ -2,13 +2,9 @@
   NOTE: This is the global export file for rxjs v6 and higher.
  */
 
-/* rxjs */
+/* rxjs and rxjs.operators */
 export * from './Rx';
 
-/* rxjs.operators */
-import * as _operators from 'rxjs/operators';
-export const operators = _operators;
-
 /* rxjs.testing */
 import * as _testing from 'rxjs/testing';
 export const testing = _testing;