message: fix(`mergeMapTo`): remove redundant/unused generic
diff: @@ -3,7 +3,7 @@ import { mergeMap } from './mergeMap';
  import { ObservableInput } from '../types';
  /* tslint:disable:max-line-length */
  -export function mergeMapTo<T, O extends ObservableInput<any>>(innerObservable: O, concurrent?: number): OperatorFunction<any, ObservedValueOf<O>>;
  +export function mergeMapTo<O extends ObservableInput<any>>(innerObservable: O, concurrent?: number): OperatorFunction<any, ObservedValueOf<O>>;
  /** @deprecated */
  export function mergeMapTo<T, R, O extends ObservableInput<any>>(innerObservable: O, resultSelector: (outerValue: T, innerValue: ObservedValueOf<O>, outerIndex: number, innerIndex: number) => R, concurrent?: number): OperatorFunction<T, R>;
  /* tslint:enable:max-line-length */
  