jquery.byteLimit: Fix infinite loop if text is longer than max

When the length of the returned text of the callback is longer than the
max, the slicing of the input text, should not go into a endless loop.

Without this change, the added unit tests would fail as a result of
the infinite loop.

Bug: 41450
Change-Id: Iad84522659ab160e18828cbfc463db83bc7e4795
Merge "jquery.byteLimit: Fix infinite loop if text is longer than max"