Bug/Icon Request: Spacer/Blank

[jozeck]

It is a duplicate, but after releasing version 5 it now makes sense

When I use code beneath to create empty spacer with included JS for 4.x compatibility:
<i class="fas fa-fw"></i>
as a result I got "unknown icon":

#1606
#11818
#10495

[tagliala]

@robmadole could you please take a look at this?

[robmadole]

We normally recommend that the showMissingIcons config be set to false (which would hide this icon). However we have a regression on that so I've filed #12581.

After that issue is fixed it should just take a configuration change to hide the icon.

<script>FontAwesomeConfig = { showMissingIcons: false }</script>