[Bug Report] Select Remote Search component don't have same behaviour when multiple-select attribute is activated

### Element UI version
2.13.0

### OS/Browsers version
Chrome, Safari, Brave

### Vue version
2.6.11

### Reproduction Link
https://codepen.io/grgurev/pen/bGdbOrO

### Steps to reproduce
Add "multiple" attribute on remote search Select component.

### What is Expected?
It is expected that "No data" text is displayed after there is no data to display and not before "Loading" text.

### What is actually happening?
After typing first letter the "No data" text is displayed shortly before loading text "Loading". The correct behaviour is implemented in regular remote search, without "multiple" attribute.